1 //===------- CGObjCGNU.cpp - Emit LLVM Code from ASTs for a Module --------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This provides Objective-C code generation targeting the GNU runtime. The
11 // class in this file generates structures used by the GNU Objective-C runtime
12 // library. These structures are defined in objc/objc.h and objc/objc-api.h in
13 // the GNU runtime distribution.
15 //===----------------------------------------------------------------------===//
17 #include "CGObjCRuntime.h"
18 #include "CodeGenModule.h"
19 #include "CodeGenFunction.h"
20 #include "CGCleanup.h"
22 #include "clang/AST/ASTContext.h"
23 #include "clang/AST/Decl.h"
24 #include "clang/AST/DeclObjC.h"
25 #include "clang/AST/RecordLayout.h"
26 #include "clang/AST/StmtObjC.h"
27 #include "clang/Basic/SourceManager.h"
28 #include "clang/Basic/FileManager.h"
30 #include "llvm/Intrinsics.h"
31 #include "llvm/Module.h"
32 #include "llvm/LLVMContext.h"
33 #include "llvm/ADT/SmallVector.h"
34 #include "llvm/ADT/StringMap.h"
35 #include "llvm/Support/CallSite.h"
36 #include "llvm/Support/Compiler.h"
37 #include "llvm/Target/TargetData.h"
42 using namespace clang;
43 using namespace CodeGen;
48 /// Class that lazily initialises the runtime function. Avoids inserting the
49 /// types and the function declaration into a module if they're not used, and
50 /// avoids constructing the type more than once if it's used more than once.
51 class LazyRuntimeFunction {
53 std::vector<const llvm::Type*> ArgTys;
54 const char *FunctionName;
55 llvm::Constant *Function;
57 /// Constructor leaves this class uninitialized, because it is intended to
58 /// be used as a field in another class and not all of the types that are
59 /// used as arguments will necessarily be available at construction time.
60 LazyRuntimeFunction() : CGM(0), FunctionName(0), Function(0) {}
62 /// Initialises the lazy function with the name, return type, and the types
65 void init(CodeGenModule *Mod, const char *name,
66 const llvm::Type *RetTy, ...) {
72 va_start(Args, RetTy);
73 while (const llvm::Type *ArgTy = va_arg(Args, const llvm::Type*))
74 ArgTys.push_back(ArgTy);
76 // Push the return type on at the end so we can pop it off easily
77 ArgTys.push_back(RetTy);
79 /// Overloaded cast operator, allows the class to be implicitly cast to an
81 operator llvm::Constant*() {
83 if (0 == FunctionName) return 0;
84 // We put the return type on the end of the vector, so pop it back off
85 const llvm::Type *RetTy = ArgTys.back();
87 llvm::FunctionType *FTy = llvm::FunctionType::get(RetTy, ArgTys, false);
89 cast<llvm::Constant>(CGM->CreateRuntimeFunction(FTy, FunctionName));
90 // We won't need to use the types again, so we may as well clean up the
96 operator llvm::Function*() {
97 return cast<llvm::Function>((llvm::Constant*)*this);
103 /// GNU Objective-C runtime code generation. This class implements the parts of
104 /// Objective-C support that are specific to the GNU family of runtimes (GCC and
106 class CGObjCGNU : public CGObjCRuntime {
108 /// The module that is using this class
110 /// The LLVM module into which output is inserted
111 llvm::Module &TheModule;
112 /// strut objc_super. Used for sending messages to super. This structure
113 /// contains the receiver (object) and the expected class.
114 const llvm::StructType *ObjCSuperTy;
115 /// struct objc_super*. The type of the argument to the superclass message
116 /// lookup functions.
117 const llvm::PointerType *PtrToObjCSuperTy;
118 /// LLVM type for selectors. Opaque pointer (i8*) unless a header declaring
119 /// SEL is included in a header somewhere, in which case it will be whatever
120 /// type is declared in that header, most likely {i8*, i8*}.
121 const llvm::PointerType *SelectorTy;
122 /// LLVM i8 type. Cached here to avoid repeatedly getting it in all of the
123 /// places where it's used
124 const llvm::IntegerType *Int8Ty;
125 /// Pointer to i8 - LLVM type of char*, for all of the places where the
126 /// runtime needs to deal with C strings.
127 const llvm::PointerType *PtrToInt8Ty;
128 /// Instance Method Pointer type. This is a pointer to a function that takes,
129 /// at a minimum, an object and a selector, and is the generic type for
130 /// Objective-C methods. Due to differences between variadic / non-variadic
131 /// calling conventions, it must always be cast to the correct type before
132 /// actually being used.
133 const llvm::PointerType *IMPTy;
134 /// Type of an untyped Objective-C object. Clang treats id as a built-in type
135 /// when compiling Objective-C code, so this may be an opaque pointer (i8*),
136 /// but if the runtime header declaring it is included then it may be a
137 /// pointer to a structure.
138 const llvm::PointerType *IdTy;
139 /// Pointer to a pointer to an Objective-C object. Used in the new ABI
140 /// message lookup function and some GC-related functions.
141 const llvm::PointerType *PtrToIdTy;
142 /// The clang type of id. Used when using the clang CGCall infrastructure to
143 /// call Objective-C methods.
145 /// LLVM type for C int type.
146 const llvm::IntegerType *IntTy;
147 /// LLVM type for an opaque pointer. This is identical to PtrToInt8Ty, but is
148 /// used in the code to document the difference between i8* meaning a pointer
149 /// to a C string and i8* meaning a pointer to some opaque type.
150 const llvm::PointerType *PtrTy;
151 /// LLVM type for C long type. The runtime uses this in a lot of places where
152 /// it should be using intptr_t, but we can't fix this without breaking
153 /// compatibility with GCC...
154 const llvm::IntegerType *LongTy;
155 /// LLVM type for C size_t. Used in various runtime data structures.
156 const llvm::IntegerType *SizeTy;
157 /// LLVM type for C ptrdiff_t. Mainly used in property accessor functions.
158 const llvm::IntegerType *PtrDiffTy;
159 /// LLVM type for C int*. Used for GCC-ABI-compatible non-fragile instance
161 const llvm::PointerType *PtrToIntTy;
162 /// LLVM type for Objective-C BOOL type.
163 const llvm::Type *BoolTy;
164 /// Metadata kind used to tie method lookups to message sends. The GNUstep
165 /// runtime provides some LLVM passes that can use this to do things like
166 /// automatic IMP caching and speculative inlining.
167 unsigned msgSendMDKind;
168 /// Helper function that generates a constant string and returns a pointer to
169 /// the start of the string. The result of this function can be used anywhere
170 /// where the C code specifies const char*.
171 llvm::Constant *MakeConstantString(const std::string &Str,
172 const std::string &Name="") {
173 llvm::Constant *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str());
174 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros, 2);
176 /// Emits a linkonce_odr string, whose name is the prefix followed by the
177 /// string value. This allows the linker to combine the strings between
178 /// different modules. Used for EH typeinfo names, selector strings, and a
179 /// few other things.
180 llvm::Constant *ExportUniqueString(const std::string &Str,
181 const std::string prefix) {
182 std::string name = prefix + Str;
183 llvm::Constant *ConstStr = TheModule.getGlobalVariable(name);
185 llvm::Constant *value = llvm::ConstantArray::get(VMContext, Str, true);
186 ConstStr = new llvm::GlobalVariable(TheModule, value->getType(), true,
187 llvm::GlobalValue::LinkOnceODRLinkage, value, prefix + Str);
189 return llvm::ConstantExpr::getGetElementPtr(ConstStr, Zeros, 2);
191 /// Generates a global structure, initialized by the elements in the vector.
192 /// The element types must match the types of the structure elements in the
194 llvm::GlobalVariable *MakeGlobal(const llvm::StructType *Ty,
195 std::vector<llvm::Constant*> &V,
196 llvm::StringRef Name="",
197 llvm::GlobalValue::LinkageTypes linkage
198 =llvm::GlobalValue::InternalLinkage) {
199 llvm::Constant *C = llvm::ConstantStruct::get(Ty, V);
200 return new llvm::GlobalVariable(TheModule, Ty, false,
203 /// Generates a global array. The vector must contain the same number of
204 /// elements that the array type declares, of the type specified as the array
206 llvm::GlobalVariable *MakeGlobal(const llvm::ArrayType *Ty,
207 std::vector<llvm::Constant*> &V,
208 llvm::StringRef Name="",
209 llvm::GlobalValue::LinkageTypes linkage
210 =llvm::GlobalValue::InternalLinkage) {
211 llvm::Constant *C = llvm::ConstantArray::get(Ty, V);
212 return new llvm::GlobalVariable(TheModule, Ty, false,
215 /// Generates a global array, inferring the array type from the specified
216 /// element type and the size of the initialiser.
217 llvm::GlobalVariable *MakeGlobalArray(const llvm::Type *Ty,
218 std::vector<llvm::Constant*> &V,
219 llvm::StringRef Name="",
220 llvm::GlobalValue::LinkageTypes linkage
221 =llvm::GlobalValue::InternalLinkage) {
222 llvm::ArrayType *ArrayTy = llvm::ArrayType::get(Ty, V.size());
223 return MakeGlobal(ArrayTy, V, Name, linkage);
225 /// Ensures that the value has the required type, by inserting a bitcast if
226 /// required. This function lets us avoid inserting bitcasts that are
228 llvm::Value* EnforceType(CGBuilderTy B, llvm::Value *V, const llvm::Type *Ty){
229 if (V->getType() == Ty) return V;
230 return B.CreateBitCast(V, Ty);
232 // Some zeros used for GEPs in lots of places.
233 llvm::Constant *Zeros[2];
234 /// Null pointer value. Mainly used as a terminator in various arrays.
235 llvm::Constant *NULLPtr;
237 llvm::LLVMContext &VMContext;
239 /// Placeholder for the class. Lots of things refer to the class before we've
240 /// actually emitted it. We use this alias as a placeholder, and then replace
241 /// it with a pointer to the class structure before finally emitting the
243 llvm::GlobalAlias *ClassPtrAlias;
244 /// Placeholder for the metaclass. Lots of things refer to the class before
245 /// we've / actually emitted it. We use this alias as a placeholder, and then
246 /// replace / it with a pointer to the metaclass structure before finally
247 /// emitting the / module.
248 llvm::GlobalAlias *MetaClassPtrAlias;
249 /// All of the classes that have been generated for this compilation units.
250 std::vector<llvm::Constant*> Classes;
251 /// All of the categories that have been generated for this compilation units.
252 std::vector<llvm::Constant*> Categories;
253 /// All of the Objective-C constant strings that have been generated for this
254 /// compilation units.
255 std::vector<llvm::Constant*> ConstantStrings;
256 /// Map from string values to Objective-C constant strings in the output.
257 /// Used to prevent emitting Objective-C strings more than once. This should
258 /// not be required at all - CodeGenModule should manage this list.
259 llvm::StringMap<llvm::Constant*> ObjCStrings;
260 /// All of the protocols that have been declared.
261 llvm::StringMap<llvm::Constant*> ExistingProtocols;
262 /// For each variant of a selector, we store the type encoding and a
263 /// placeholder value. For an untyped selector, the type will be the empty
264 /// string. Selector references are all done via the module's selector table,
265 /// so we create an alias as a placeholder and then replace it with the real
267 typedef std::pair<std::string, llvm::GlobalAlias*> TypedSelector;
268 /// Type of the selector map. This is roughly equivalent to the structure
269 /// used in the GNUstep runtime, which maintains a list of all of the valid
270 /// types for a selector in a table.
271 typedef llvm::DenseMap<Selector, llvm::SmallVector<TypedSelector, 2> >
273 /// A map from selectors to selector types. This allows us to emit all
274 /// selectors of the same name and type together.
275 SelectorMap SelectorTable;
277 /// Selectors related to memory management. When compiling in GC mode, we
279 Selector RetainSel, ReleaseSel, AutoreleaseSel;
280 /// Runtime functions used for memory management in GC mode. Note that clang
281 /// supports code generation for calling these functions, but neither GNU
282 /// runtime actually supports this API properly yet.
283 LazyRuntimeFunction IvarAssignFn, StrongCastAssignFn, MemMoveFn, WeakReadFn,
284 WeakAssignFn, GlobalAssignFn;
287 /// Function used for throwing Objective-C exceptions.
288 LazyRuntimeFunction ExceptionThrowFn;
289 /// Function used for rethrowing exceptions, used at the end of @finally or
290 /// @synchronize blocks.
291 LazyRuntimeFunction ExceptionReThrowFn;
292 /// Function called when entering a catch function. This is required for
293 /// differentiating Objective-C exceptions and foreign exceptions.
294 LazyRuntimeFunction EnterCatchFn;
295 /// Function called when exiting from a catch block. Used to do exception
297 LazyRuntimeFunction ExitCatchFn;
298 /// Function called when entering an @synchronize block. Acquires the lock.
299 LazyRuntimeFunction SyncEnterFn;
300 /// Function called when exiting an @synchronize block. Releases the lock.
301 LazyRuntimeFunction SyncExitFn;
305 /// Function called if fast enumeration detects that the collection is
306 /// modified during the update.
307 LazyRuntimeFunction EnumerationMutationFn;
308 /// Function for implementing synthesized property getters that return an
310 LazyRuntimeFunction GetPropertyFn;
311 /// Function for implementing synthesized property setters that return an
313 LazyRuntimeFunction SetPropertyFn;
314 /// Function used for non-object declared property getters.
315 LazyRuntimeFunction GetStructPropertyFn;
316 /// Function used for non-object declared property setters.
317 LazyRuntimeFunction SetStructPropertyFn;
319 /// The version of the runtime that this class targets. Must match the
320 /// version in the runtime.
322 /// The version of the protocol class. Used to differentiate between ObjC1
323 /// and ObjC2 protocols. Objective-C 1 protocols can not contain optional
324 /// components and can not contain declared properties. We always emit
325 /// Objective-C 2 property structures, but we have to pretend that they're
326 /// Objective-C 1 property structures when targeting the GCC runtime or it
328 const int ProtocolVersion;
330 /// Generates an instance variable list structure. This is a structure
331 /// containing a size and an array of structures containing instance variable
332 /// metadata. This is used purely for introspection in the fragile ABI. In
333 /// the non-fragile ABI, it's used for instance variable fixup.
334 llvm::Constant *GenerateIvarList(
335 const llvm::SmallVectorImpl<llvm::Constant *> &IvarNames,
336 const llvm::SmallVectorImpl<llvm::Constant *> &IvarTypes,
337 const llvm::SmallVectorImpl<llvm::Constant *> &IvarOffsets);
338 /// Generates a method list structure. This is a structure containing a size
339 /// and an array of structures containing method metadata.
341 /// This structure is used by both classes and categories, and contains a next
342 /// pointer allowing them to be chained together in a linked list.
343 llvm::Constant *GenerateMethodList(const llvm::StringRef &ClassName,
344 const llvm::StringRef &CategoryName,
345 const llvm::SmallVectorImpl<Selector> &MethodSels,
346 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes,
347 bool isClassMethodList);
348 /// Emits an empty protocol. This is used for @protocol() where no protocol
349 /// is found. The runtime will (hopefully) fix up the pointer to refer to the
351 llvm::Constant *GenerateEmptyProtocol(const std::string &ProtocolName);
352 /// Generates a list of property metadata structures. This follows the same
353 /// pattern as method and instance variable metadata lists.
354 llvm::Constant *GeneratePropertyList(const ObjCImplementationDecl *OID,
355 llvm::SmallVectorImpl<Selector> &InstanceMethodSels,
356 llvm::SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes);
357 /// Generates a list of referenced protocols. Classes, categories, and
358 /// protocols all use this structure.
359 llvm::Constant *GenerateProtocolList(
360 const llvm::SmallVectorImpl<std::string> &Protocols);
361 /// To ensure that all protocols are seen by the runtime, we add a category on
362 /// a class defined in the runtime, declaring no methods, but adopting the
363 /// protocols. This is a horribly ugly hack, but it allows us to collect all
364 /// of the protocols without changing the ABI.
365 void GenerateProtocolHolderCategory(void);
366 /// Generates a class structure.
367 llvm::Constant *GenerateClassStructure(
368 llvm::Constant *MetaClass,
369 llvm::Constant *SuperClass,
372 llvm::Constant *Version,
373 llvm::Constant *InstanceSize,
374 llvm::Constant *IVars,
375 llvm::Constant *Methods,
376 llvm::Constant *Protocols,
377 llvm::Constant *IvarOffsets,
378 llvm::Constant *Properties,
380 /// Generates a method list. This is used by protocols to define the required
381 /// and optional methods.
382 llvm::Constant *GenerateProtocolMethodList(
383 const llvm::SmallVectorImpl<llvm::Constant *> &MethodNames,
384 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes);
385 /// Returns a selector with the specified type encoding. An empty string is
386 /// used to return an untyped selector (with the types field set to NULL).
387 llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel,
388 const std::string &TypeEncoding, bool lval);
389 /// Returns the variable used to store the offset of an instance variable.
390 llvm::GlobalVariable *ObjCIvarOffsetVariable(const ObjCInterfaceDecl *ID,
391 const ObjCIvarDecl *Ivar);
392 /// Emits a reference to a class. This allows the linker to object if there
393 /// is no class of the matching name.
394 void EmitClassRef(const std::string &className);
396 /// Looks up the method for sending a message to the specified object. This
397 /// mechanism differs between the GCC and GNU runtimes, so this method must be
398 /// overridden in subclasses.
399 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF,
400 llvm::Value *&Receiver,
402 llvm::MDNode *node) = 0;
403 /// Looks up the method for sending a message to a superclass. This mechanism
404 /// differs between the GCC and GNU runtimes, so this method must be
405 /// overridden in subclasses.
406 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF,
407 llvm::Value *ObjCSuper,
408 llvm::Value *cmd) = 0;
410 CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
411 unsigned protocolClassVersion);
413 virtual llvm::Constant *GenerateConstantString(const StringLiteral *);
416 GenerateMessageSend(CodeGenFunction &CGF,
417 ReturnValueSlot Return,
420 llvm::Value *Receiver,
421 const CallArgList &CallArgs,
422 const ObjCInterfaceDecl *Class,
423 const ObjCMethodDecl *Method);
425 GenerateMessageSendSuper(CodeGenFunction &CGF,
426 ReturnValueSlot Return,
429 const ObjCInterfaceDecl *Class,
431 llvm::Value *Receiver,
433 const CallArgList &CallArgs,
434 const ObjCMethodDecl *Method);
435 virtual llvm::Value *GetClass(CGBuilderTy &Builder,
436 const ObjCInterfaceDecl *OID);
437 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, Selector Sel,
439 virtual llvm::Value *GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl
441 virtual llvm::Constant *GetEHType(QualType T);
443 virtual llvm::Function *GenerateMethod(const ObjCMethodDecl *OMD,
444 const ObjCContainerDecl *CD);
445 virtual void GenerateCategory(const ObjCCategoryImplDecl *CMD);
446 virtual void GenerateClass(const ObjCImplementationDecl *ClassDecl);
447 virtual llvm::Value *GenerateProtocolRef(CGBuilderTy &Builder,
448 const ObjCProtocolDecl *PD);
449 virtual void GenerateProtocol(const ObjCProtocolDecl *PD);
450 virtual llvm::Function *ModuleInitFunction();
451 virtual llvm::Constant *GetPropertyGetFunction();
452 virtual llvm::Constant *GetPropertySetFunction();
453 virtual llvm::Constant *GetSetStructFunction();
454 virtual llvm::Constant *GetGetStructFunction();
455 virtual llvm::Constant *EnumerationMutationFunction();
457 virtual void EmitTryStmt(CodeGenFunction &CGF,
458 const ObjCAtTryStmt &S);
459 virtual void EmitSynchronizedStmt(CodeGenFunction &CGF,
460 const ObjCAtSynchronizedStmt &S);
461 virtual void EmitThrowStmt(CodeGenFunction &CGF,
462 const ObjCAtThrowStmt &S);
463 virtual llvm::Value * EmitObjCWeakRead(CodeGenFunction &CGF,
464 llvm::Value *AddrWeakObj);
465 virtual void EmitObjCWeakAssign(CodeGenFunction &CGF,
466 llvm::Value *src, llvm::Value *dst);
467 virtual void EmitObjCGlobalAssign(CodeGenFunction &CGF,
468 llvm::Value *src, llvm::Value *dest,
469 bool threadlocal=false);
470 virtual void EmitObjCIvarAssign(CodeGenFunction &CGF,
471 llvm::Value *src, llvm::Value *dest,
472 llvm::Value *ivarOffset);
473 virtual void EmitObjCStrongCastAssign(CodeGenFunction &CGF,
474 llvm::Value *src, llvm::Value *dest);
475 virtual void EmitGCMemmoveCollectable(CodeGenFunction &CGF,
476 llvm::Value *DestPtr,
479 virtual LValue EmitObjCValueForIvar(CodeGenFunction &CGF,
481 llvm::Value *BaseValue,
482 const ObjCIvarDecl *Ivar,
483 unsigned CVRQualifiers);
484 virtual llvm::Value *EmitIvarOffset(CodeGenFunction &CGF,
485 const ObjCInterfaceDecl *Interface,
486 const ObjCIvarDecl *Ivar);
487 virtual llvm::Constant *BuildGCBlockLayout(CodeGenModule &CGM,
488 const CGBlockInfo &blockInfo) {
492 virtual llvm::GlobalVariable *GetClassGlobal(const std::string &Name) {
496 /// Class representing the legacy GCC Objective-C ABI. This is the default when
497 /// -fobjc-nonfragile-abi is not specified.
499 /// The GCC ABI target actually generates code that is approximately compatible
500 /// with the new GNUstep runtime ABI, but refrains from using any features that
501 /// would not work with the GCC runtime. For example, clang always generates
502 /// the extended form of the class structure, and the extra fields are simply
503 /// ignored by GCC libobjc.
504 class CGObjCGCC : public CGObjCGNU {
505 /// The GCC ABI message lookup function. Returns an IMP pointing to the
506 /// method implementation for this message.
507 LazyRuntimeFunction MsgLookupFn;
508 /// The GCC ABI superclass message lookup function. Takes a pointer to a
509 /// structure describing the receiver and the class, and a selector as
510 /// arguments. Returns the IMP for the corresponding method.
511 LazyRuntimeFunction MsgLookupSuperFn;
513 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF,
514 llvm::Value *&Receiver,
516 llvm::MDNode *node) {
517 CGBuilderTy &Builder = CGF.Builder;
518 llvm::Value *imp = Builder.CreateCall2(MsgLookupFn,
519 EnforceType(Builder, Receiver, IdTy),
520 EnforceType(Builder, cmd, SelectorTy));
521 cast<llvm::CallInst>(imp)->setMetadata(msgSendMDKind, node);
524 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF,
525 llvm::Value *ObjCSuper,
527 CGBuilderTy &Builder = CGF.Builder;
528 llvm::Value *lookupArgs[] = {EnforceType(Builder, ObjCSuper,
529 PtrToObjCSuperTy), cmd};
530 return Builder.CreateCall(MsgLookupSuperFn, lookupArgs, lookupArgs+2);
533 CGObjCGCC(CodeGenModule &Mod) : CGObjCGNU(Mod, 8, 2) {
534 // IMP objc_msg_lookup(id, SEL);
535 MsgLookupFn.init(&CGM, "objc_msg_lookup", IMPTy, IdTy, SelectorTy, NULL);
536 // IMP objc_msg_lookup_super(struct objc_super*, SEL);
537 MsgLookupSuperFn.init(&CGM, "objc_msg_lookup_super", IMPTy,
538 PtrToObjCSuperTy, SelectorTy, NULL);
541 /// Class used when targeting the new GNUstep runtime ABI.
542 class CGObjCGNUstep : public CGObjCGNU {
543 /// The slot lookup function. Returns a pointer to a cacheable structure
544 /// that contains (among other things) the IMP.
545 LazyRuntimeFunction SlotLookupFn;
546 /// The GNUstep ABI superclass message lookup function. Takes a pointer to
547 /// a structure describing the receiver and the class, and a selector as
548 /// arguments. Returns the slot for the corresponding method. Superclass
549 /// message lookup rarely changes, so this is a good caching opportunity.
550 LazyRuntimeFunction SlotLookupSuperFn;
551 /// Type of an slot structure pointer. This is returned by the various
552 /// lookup functions.
555 virtual llvm::Value *LookupIMP(CodeGenFunction &CGF,
556 llvm::Value *&Receiver,
558 llvm::MDNode *node) {
559 CGBuilderTy &Builder = CGF.Builder;
560 llvm::Function *LookupFn = SlotLookupFn;
562 // Store the receiver on the stack so that we can reload it later
563 llvm::Value *ReceiverPtr = CGF.CreateTempAlloca(Receiver->getType());
564 Builder.CreateStore(Receiver, ReceiverPtr);
568 if (isa<ObjCMethodDecl>(CGF.CurCodeDecl)) {
569 self = CGF.LoadObjCSelf();
571 self = llvm::ConstantPointerNull::get(IdTy);
574 // The lookup function is guaranteed not to capture the receiver pointer.
575 LookupFn->setDoesNotCapture(1);
577 llvm::CallInst *slot =
578 Builder.CreateCall3(LookupFn,
579 EnforceType(Builder, ReceiverPtr, PtrToIdTy),
580 EnforceType(Builder, cmd, SelectorTy),
581 EnforceType(Builder, self, IdTy));
582 slot->setOnlyReadsMemory();
583 slot->setMetadata(msgSendMDKind, node);
585 // Load the imp from the slot
586 llvm::Value *imp = Builder.CreateLoad(Builder.CreateStructGEP(slot, 4));
588 // The lookup function may have changed the receiver, so make sure we use
590 Receiver = Builder.CreateLoad(ReceiverPtr, true);
593 virtual llvm::Value *LookupIMPSuper(CodeGenFunction &CGF,
594 llvm::Value *ObjCSuper,
596 CGBuilderTy &Builder = CGF.Builder;
597 llvm::Value *lookupArgs[] = {ObjCSuper, cmd};
599 llvm::CallInst *slot = Builder.CreateCall(SlotLookupSuperFn, lookupArgs,
601 slot->setOnlyReadsMemory();
603 return Builder.CreateLoad(Builder.CreateStructGEP(slot, 4));
606 CGObjCGNUstep(CodeGenModule &Mod) : CGObjCGNU(Mod, 9, 3) {
607 llvm::StructType *SlotStructTy = llvm::StructType::get(VMContext, PtrTy,
608 PtrTy, PtrTy, IntTy, IMPTy, NULL);
609 SlotTy = llvm::PointerType::getUnqual(SlotStructTy);
610 // Slot_t objc_msg_lookup_sender(id *receiver, SEL selector, id sender);
611 SlotLookupFn.init(&CGM, "objc_msg_lookup_sender", SlotTy, PtrToIdTy,
612 SelectorTy, IdTy, NULL);
613 // Slot_t objc_msg_lookup_super(struct objc_super*, SEL);
614 SlotLookupSuperFn.init(&CGM, "objc_slot_lookup_super", SlotTy,
615 PtrToObjCSuperTy, SelectorTy, NULL);
616 // If we're in ObjC++ mode, then we want to make
617 if (CGM.getLangOptions().CPlusPlus) {
618 const llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
619 // void *__cxa_begin_catch(void *e)
620 EnterCatchFn.init(&CGM, "__cxa_begin_catch", PtrTy, PtrTy, NULL);
621 // void __cxa_end_catch(void)
622 EnterCatchFn.init(&CGM, "__cxa_end_catch", VoidTy, NULL);
623 // void _Unwind_Resume_or_Rethrow(void*)
624 ExceptionReThrowFn.init(&CGM, "_Unwind_Resume_or_Rethrow", VoidTy, PtrTy, NULL);
629 } // end anonymous namespace
632 /// Emits a reference to a dummy variable which is emitted with each class.
633 /// This ensures that a linker error will be generated when trying to link
634 /// together modules where a referenced class is not defined.
635 void CGObjCGNU::EmitClassRef(const std::string &className) {
636 std::string symbolRef = "__objc_class_ref_" + className;
637 // Don't emit two copies of the same symbol
638 if (TheModule.getGlobalVariable(symbolRef))
640 std::string symbolName = "__objc_class_name_" + className;
641 llvm::GlobalVariable *ClassSymbol = TheModule.getGlobalVariable(symbolName);
643 ClassSymbol = new llvm::GlobalVariable(TheModule, LongTy, false,
644 llvm::GlobalValue::ExternalLinkage, 0, symbolName);
646 new llvm::GlobalVariable(TheModule, ClassSymbol->getType(), true,
647 llvm::GlobalValue::WeakAnyLinkage, ClassSymbol, symbolRef);
650 static std::string SymbolNameForMethod(const llvm::StringRef &ClassName,
651 const llvm::StringRef &CategoryName, const Selector MethodName,
652 bool isClassMethod) {
653 std::string MethodNameColonStripped = MethodName.getAsString();
654 std::replace(MethodNameColonStripped.begin(), MethodNameColonStripped.end(),
656 return (llvm::Twine(isClassMethod ? "_c_" : "_i_") + ClassName + "_" +
657 CategoryName + "_" + MethodNameColonStripped).str();
660 CGObjCGNU::CGObjCGNU(CodeGenModule &cgm, unsigned runtimeABIVersion,
661 unsigned protocolClassVersion)
662 : CGM(cgm), TheModule(CGM.getModule()), VMContext(cgm.getLLVMContext()),
663 ClassPtrAlias(0), MetaClassPtrAlias(0), RuntimeVersion(runtimeABIVersion),
664 ProtocolVersion(protocolClassVersion) {
666 msgSendMDKind = VMContext.getMDKindID("GNUObjCMessageSend");
668 CodeGenTypes &Types = CGM.getTypes();
669 IntTy = cast<llvm::IntegerType>(
670 Types.ConvertType(CGM.getContext().IntTy));
671 LongTy = cast<llvm::IntegerType>(
672 Types.ConvertType(CGM.getContext().LongTy));
673 SizeTy = cast<llvm::IntegerType>(
674 Types.ConvertType(CGM.getContext().getSizeType()));
675 PtrDiffTy = cast<llvm::IntegerType>(
676 Types.ConvertType(CGM.getContext().getPointerDiffType()));
677 BoolTy = CGM.getTypes().ConvertType(CGM.getContext().BoolTy);
679 Int8Ty = llvm::Type::getInt8Ty(VMContext);
680 // C string type. Used in lots of places.
681 PtrToInt8Ty = llvm::PointerType::getUnqual(Int8Ty);
683 Zeros[0] = llvm::ConstantInt::get(LongTy, 0);
685 NULLPtr = llvm::ConstantPointerNull::get(PtrToInt8Ty);
686 // Get the selector Type.
687 QualType selTy = CGM.getContext().getObjCSelType();
688 if (QualType() == selTy) {
689 SelectorTy = PtrToInt8Ty;
691 SelectorTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(selTy));
694 PtrToIntTy = llvm::PointerType::getUnqual(IntTy);
698 QualType UnqualIdTy = CGM.getContext().getObjCIdType();
699 ASTIdTy = CanQualType();
700 if (UnqualIdTy != QualType()) {
701 ASTIdTy = CGM.getContext().getCanonicalType(UnqualIdTy);
702 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
706 PtrToIdTy = llvm::PointerType::getUnqual(IdTy);
708 ObjCSuperTy = llvm::StructType::get(VMContext, IdTy, IdTy, NULL);
709 PtrToObjCSuperTy = llvm::PointerType::getUnqual(ObjCSuperTy);
711 const llvm::Type *VoidTy = llvm::Type::getVoidTy(VMContext);
713 // void objc_exception_throw(id);
714 ExceptionThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL);
715 ExceptionReThrowFn.init(&CGM, "objc_exception_throw", VoidTy, IdTy, NULL);
716 // int objc_sync_enter(id);
717 SyncEnterFn.init(&CGM, "objc_sync_enter", IntTy, IdTy, NULL);
718 // int objc_sync_exit(id);
719 SyncExitFn.init(&CGM, "objc_sync_exit", IntTy, IdTy, NULL);
721 // void objc_enumerationMutation (id)
722 EnumerationMutationFn.init(&CGM, "objc_enumerationMutation", VoidTy,
725 // id objc_getProperty(id, SEL, ptrdiff_t, BOOL)
726 GetPropertyFn.init(&CGM, "objc_getProperty", IdTy, IdTy, SelectorTy,
727 PtrDiffTy, BoolTy, NULL);
728 // void objc_setProperty(id, SEL, ptrdiff_t, id, BOOL, BOOL)
729 SetPropertyFn.init(&CGM, "objc_setProperty", VoidTy, IdTy, SelectorTy,
730 PtrDiffTy, IdTy, BoolTy, BoolTy, NULL);
731 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
732 GetStructPropertyFn.init(&CGM, "objc_getPropertyStruct", VoidTy, PtrTy, PtrTy,
733 PtrDiffTy, BoolTy, BoolTy, NULL);
734 // void objc_setPropertyStruct(void*, void*, ptrdiff_t, BOOL, BOOL)
735 SetStructPropertyFn.init(&CGM, "objc_setPropertyStruct", VoidTy, PtrTy, PtrTy,
736 PtrDiffTy, BoolTy, BoolTy, NULL);
739 const llvm::Type *IMPArgs[] = { IdTy, SelectorTy };
740 IMPTy = llvm::PointerType::getUnqual(llvm::FunctionType::get(IdTy, IMPArgs,
743 // Don't bother initialising the GC stuff unless we're compiling in GC mode
744 if (CGM.getLangOptions().getGCMode() != LangOptions::NonGC) {
745 // This is a bit of an hack. We should sort this out by having a proper
746 // CGObjCGNUstep subclass for GC, but we may want to really support the old
747 // ABI and GC added in ObjectiveC2.framework, so we fudge it a bit for now
749 // Get selectors needed in GC mode
750 RetainSel = GetNullarySelector("retain", CGM.getContext());
751 ReleaseSel = GetNullarySelector("release", CGM.getContext());
752 AutoreleaseSel = GetNullarySelector("autorelease", CGM.getContext());
754 // Get functions needed in GC mode
756 // id objc_assign_ivar(id, id, ptrdiff_t);
757 IvarAssignFn.init(&CGM, "objc_assign_ivar", IdTy, IdTy, IdTy, PtrDiffTy,
759 // id objc_assign_strongCast (id, id*)
760 StrongCastAssignFn.init(&CGM, "objc_assign_strongCast", IdTy, IdTy,
762 // id objc_assign_global(id, id*);
763 GlobalAssignFn.init(&CGM, "objc_assign_global", IdTy, IdTy, PtrToIdTy,
765 // id objc_assign_weak(id, id*);
766 WeakAssignFn.init(&CGM, "objc_assign_weak", IdTy, IdTy, PtrToIdTy, NULL);
767 // id objc_read_weak(id*);
768 WeakReadFn.init(&CGM, "objc_read_weak", IdTy, PtrToIdTy, NULL);
769 // void *objc_memmove_collectable(void*, void *, size_t);
770 MemMoveFn.init(&CGM, "objc_memmove_collectable", PtrTy, PtrTy, PtrTy,
775 // This has to perform the lookup every time, since posing and related
776 // techniques can modify the name -> class mapping.
777 llvm::Value *CGObjCGNU::GetClass(CGBuilderTy &Builder,
778 const ObjCInterfaceDecl *OID) {
779 llvm::Value *ClassName = CGM.GetAddrOfConstantCString(OID->getNameAsString());
780 // With the incompatible ABI, this will need to be replaced with a direct
781 // reference to the class symbol. For the compatible nonfragile ABI we are
782 // still performing this lookup at run time but emitting the symbol for the
783 // class externally so that we can make the switch later.
784 EmitClassRef(OID->getNameAsString());
785 ClassName = Builder.CreateStructGEP(ClassName, 0);
787 llvm::Constant *ClassLookupFn =
788 CGM.CreateRuntimeFunction(llvm::FunctionType::get(IdTy, PtrToInt8Ty, true),
789 "objc_lookup_class");
790 return Builder.CreateCall(ClassLookupFn, ClassName);
793 llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel,
794 const std::string &TypeEncoding, bool lval) {
796 llvm::SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel];
797 llvm::GlobalAlias *SelValue = 0;
800 for (llvm::SmallVectorImpl<TypedSelector>::iterator i = Types.begin(),
801 e = Types.end() ; i!=e ; i++) {
802 if (i->first == TypeEncoding) {
803 SelValue = i->second;
808 SelValue = new llvm::GlobalAlias(SelectorTy,
809 llvm::GlobalValue::PrivateLinkage,
810 ".objc_selector_"+Sel.getAsString(), NULL,
812 Types.push_back(TypedSelector(TypeEncoding, SelValue));
816 llvm::Value *tmp = Builder.CreateAlloca(SelValue->getType());
817 Builder.CreateStore(SelValue, tmp);
823 llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, Selector Sel,
825 return GetSelector(Builder, Sel, std::string(), lval);
828 llvm::Value *CGObjCGNU::GetSelector(CGBuilderTy &Builder, const ObjCMethodDecl
830 std::string SelTypes;
831 CGM.getContext().getObjCEncodingForMethodDecl(Method, SelTypes);
832 return GetSelector(Builder, Method->getSelector(), SelTypes, false);
835 llvm::Constant *CGObjCGNU::GetEHType(QualType T) {
836 if (!CGM.getLangOptions().CPlusPlus) {
837 if (T->isObjCIdType()
838 || T->isObjCQualifiedIdType()) {
839 // With the old ABI, there was only one kind of catchall, which broke
840 // foreign exceptions. With the new ABI, we use __objc_id_typeinfo as
841 // a pointer indicating object catchalls, and NULL to indicate real
843 if (CGM.getLangOptions().ObjCNonFragileABI) {
844 return MakeConstantString("@id");
850 // All other types should be Objective-C interface pointer types.
851 const ObjCObjectPointerType *OPT =
852 T->getAs<ObjCObjectPointerType>();
853 assert(OPT && "Invalid @catch type.");
854 const ObjCInterfaceDecl *IDecl =
855 OPT->getObjectType()->getInterface();
856 assert(IDecl && "Invalid @catch type.");
857 return MakeConstantString(IDecl->getIdentifier()->getName());
859 // For Objective-C++, we want to provide the ability to catch both C++ and
860 // Objective-C objects in the same function.
862 // There's a particular fixed type info for 'id'.
863 if (T->isObjCIdType() ||
864 T->isObjCQualifiedIdType()) {
865 llvm::Constant *IDEHType =
866 CGM.getModule().getGlobalVariable("__objc_id_type_info");
869 new llvm::GlobalVariable(CGM.getModule(), PtrToInt8Ty,
871 llvm::GlobalValue::ExternalLinkage,
872 0, "__objc_id_type_info");
873 return llvm::ConstantExpr::getBitCast(IDEHType, PtrToInt8Ty);
876 const ObjCObjectPointerType *PT =
877 T->getAs<ObjCObjectPointerType>();
878 assert(PT && "Invalid @catch type.");
879 const ObjCInterfaceType *IT = PT->getInterfaceType();
880 assert(IT && "Invalid @catch type.");
881 std::string className = IT->getDecl()->getIdentifier()->getName();
883 std::string typeinfoName = "__objc_eh_typeinfo_" + className;
885 // Return the existing typeinfo if it exists
886 llvm::Constant *typeinfo = TheModule.getGlobalVariable(typeinfoName);
887 if (typeinfo) return typeinfo;
889 // Otherwise create it.
891 // vtable for gnustep::libobjc::__objc_class_type_info
892 // It's quite ugly hard-coding this. Ideally we'd generate it using the host
893 // platform's name mangling.
894 const char *vtableName = "_ZTVN7gnustep7libobjc22__objc_class_type_infoE";
895 llvm::Constant *Vtable = TheModule.getGlobalVariable(vtableName);
897 Vtable = new llvm::GlobalVariable(TheModule, PtrToInt8Ty, true,
898 llvm::GlobalValue::ExternalLinkage, 0, vtableName);
900 llvm::Constant *Two = llvm::ConstantInt::get(IntTy, 2);
901 Vtable = llvm::ConstantExpr::getGetElementPtr(Vtable, &Two, 1);
902 Vtable = llvm::ConstantExpr::getBitCast(Vtable, PtrToInt8Ty);
904 llvm::Constant *typeName =
905 ExportUniqueString(className, "__objc_eh_typename_");
907 std::vector<llvm::Constant*> fields;
908 fields.push_back(Vtable);
909 fields.push_back(typeName);
911 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty,
912 NULL), fields, "__objc_eh_typeinfo_" + className,
913 llvm::GlobalValue::LinkOnceODRLinkage);
914 return llvm::ConstantExpr::getBitCast(TI, PtrToInt8Ty);
917 /// Generate an NSConstantString object.
918 llvm::Constant *CGObjCGNU::GenerateConstantString(const StringLiteral *SL) {
920 std::string Str = SL->getString().str();
922 // Look for an existing one
923 llvm::StringMap<llvm::Constant*>::iterator old = ObjCStrings.find(Str);
924 if (old != ObjCStrings.end())
925 return old->getValue();
927 std::vector<llvm::Constant*> Ivars;
928 Ivars.push_back(NULLPtr);
929 Ivars.push_back(MakeConstantString(Str));
930 Ivars.push_back(llvm::ConstantInt::get(IntTy, Str.size()));
931 llvm::Constant *ObjCStr = MakeGlobal(
932 llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty, IntTy, NULL),
934 ObjCStr = llvm::ConstantExpr::getBitCast(ObjCStr, PtrToInt8Ty);
935 ObjCStrings[Str] = ObjCStr;
936 ConstantStrings.push_back(ObjCStr);
940 ///Generates a message send where the super is the receiver. This is a message
941 ///send to self with special delivery semantics indicating which class's method
944 CGObjCGNU::GenerateMessageSendSuper(CodeGenFunction &CGF,
945 ReturnValueSlot Return,
948 const ObjCInterfaceDecl *Class,
950 llvm::Value *Receiver,
952 const CallArgList &CallArgs,
953 const ObjCMethodDecl *Method) {
954 CGBuilderTy &Builder = CGF.Builder;
955 if (CGM.getLangOptions().getGCMode() == LangOptions::GCOnly) {
956 if (Sel == RetainSel || Sel == AutoreleaseSel) {
957 return RValue::get(EnforceType(Builder, Receiver,
958 CGM.getTypes().ConvertType(ResultType)));
960 if (Sel == ReleaseSel) {
961 return RValue::get(0);
965 llvm::Value *cmd = GetSelector(Builder, Sel);
968 CallArgList ActualArgs;
970 ActualArgs.add(RValue::get(EnforceType(Builder, Receiver, IdTy)), ASTIdTy);
971 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
972 ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end());
974 CodeGenTypes &Types = CGM.getTypes();
975 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs,
976 FunctionType::ExtInfo());
978 llvm::Value *ReceiverClass = 0;
979 if (isCategoryImpl) {
980 llvm::Constant *classLookupFunction = 0;
981 if (IsClassMessage) {
982 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
983 IdTy, PtrTy, true), "objc_get_meta_class");
985 classLookupFunction = CGM.CreateRuntimeFunction(llvm::FunctionType::get(
986 IdTy, PtrTy, true), "objc_get_class");
988 ReceiverClass = Builder.CreateCall(classLookupFunction,
989 MakeConstantString(Class->getNameAsString()));
991 // Set up global aliases for the metaclass or class pointer if they do not
992 // already exist. These will are forward-references which will be set to
993 // pointers to the class and metaclass structure created for the runtime
994 // load function. To send a message to super, we look up the value of the
995 // super_class pointer from either the class or metaclass structure.
996 if (IsClassMessage) {
997 if (!MetaClassPtrAlias) {
998 MetaClassPtrAlias = new llvm::GlobalAlias(IdTy,
999 llvm::GlobalValue::InternalLinkage, ".objc_metaclass_ref" +
1000 Class->getNameAsString(), NULL, &TheModule);
1002 ReceiverClass = MetaClassPtrAlias;
1004 if (!ClassPtrAlias) {
1005 ClassPtrAlias = new llvm::GlobalAlias(IdTy,
1006 llvm::GlobalValue::InternalLinkage, ".objc_class_ref" +
1007 Class->getNameAsString(), NULL, &TheModule);
1009 ReceiverClass = ClassPtrAlias;
1012 // Cast the pointer to a simplified version of the class structure
1013 ReceiverClass = Builder.CreateBitCast(ReceiverClass,
1014 llvm::PointerType::getUnqual(
1015 llvm::StructType::get(VMContext, IdTy, IdTy, NULL)));
1016 // Get the superclass pointer
1017 ReceiverClass = Builder.CreateStructGEP(ReceiverClass, 1);
1018 // Load the superclass pointer
1019 ReceiverClass = Builder.CreateLoad(ReceiverClass);
1020 // Construct the structure used to look up the IMP
1021 llvm::StructType *ObjCSuperTy = llvm::StructType::get(VMContext,
1022 Receiver->getType(), IdTy, NULL);
1023 llvm::Value *ObjCSuper = Builder.CreateAlloca(ObjCSuperTy);
1025 Builder.CreateStore(Receiver, Builder.CreateStructGEP(ObjCSuper, 0));
1026 Builder.CreateStore(ReceiverClass, Builder.CreateStructGEP(ObjCSuper, 1));
1028 ObjCSuper = EnforceType(Builder, ObjCSuper, PtrToObjCSuperTy);
1029 const llvm::FunctionType *impType =
1030 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false);
1033 llvm::Value *imp = LookupIMPSuper(CGF, ObjCSuper, cmd);
1034 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType));
1036 llvm::Value *impMD[] = {
1037 llvm::MDString::get(VMContext, Sel.getAsString()),
1038 llvm::MDString::get(VMContext, Class->getSuperClass()->getNameAsString()),
1039 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsClassMessage)
1041 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
1043 llvm::Instruction *call;
1044 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs,
1046 call->setMetadata(msgSendMDKind, node);
1050 /// Generate code for a message send expression.
1052 CGObjCGNU::GenerateMessageSend(CodeGenFunction &CGF,
1053 ReturnValueSlot Return,
1054 QualType ResultType,
1056 llvm::Value *Receiver,
1057 const CallArgList &CallArgs,
1058 const ObjCInterfaceDecl *Class,
1059 const ObjCMethodDecl *Method) {
1060 CGBuilderTy &Builder = CGF.Builder;
1062 // Strip out message sends to retain / release in GC mode
1063 if (CGM.getLangOptions().getGCMode() == LangOptions::GCOnly) {
1064 if (Sel == RetainSel || Sel == AutoreleaseSel) {
1065 return RValue::get(EnforceType(Builder, Receiver,
1066 CGM.getTypes().ConvertType(ResultType)));
1068 if (Sel == ReleaseSel) {
1069 return RValue::get(0);
1073 // If the return type is something that goes in an integer register, the
1074 // runtime will handle 0 returns. For other cases, we fill in the 0 value
1077 // The language spec says the result of this kind of message send is
1078 // undefined, but lots of people seem to have forgotten to read that
1079 // paragraph and insist on sending messages to nil that have structure
1080 // returns. With GCC, this generates a random return value (whatever happens
1081 // to be on the stack / in those registers at the time) on most platforms,
1082 // and generates an illegal instruction trap on SPARC. With LLVM it corrupts
1084 bool isPointerSizedReturn = (ResultType->isAnyPointerType() ||
1085 ResultType->isIntegralOrEnumerationType() || ResultType->isVoidType());
1087 llvm::BasicBlock *startBB = 0;
1088 llvm::BasicBlock *messageBB = 0;
1089 llvm::BasicBlock *continueBB = 0;
1091 if (!isPointerSizedReturn) {
1092 startBB = Builder.GetInsertBlock();
1093 messageBB = CGF.createBasicBlock("msgSend");
1094 continueBB = CGF.createBasicBlock("continue");
1096 llvm::Value *isNil = Builder.CreateICmpEQ(Receiver,
1097 llvm::Constant::getNullValue(Receiver->getType()));
1098 Builder.CreateCondBr(isNil, continueBB, messageBB);
1099 CGF.EmitBlock(messageBB);
1102 IdTy = cast<llvm::PointerType>(CGM.getTypes().ConvertType(ASTIdTy));
1105 cmd = GetSelector(Builder, Method);
1107 cmd = GetSelector(Builder, Sel);
1108 cmd = EnforceType(Builder, cmd, SelectorTy);
1109 Receiver = EnforceType(Builder, Receiver, IdTy);
1111 llvm::Value *impMD[] = {
1112 llvm::MDString::get(VMContext, Sel.getAsString()),
1113 llvm::MDString::get(VMContext, Class ? Class->getNameAsString() :""),
1114 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), Class!=0)
1116 llvm::MDNode *node = llvm::MDNode::get(VMContext, impMD);
1118 // Get the IMP to call
1119 llvm::Value *imp = LookupIMP(CGF, Receiver, cmd, node);
1121 CallArgList ActualArgs;
1122 ActualArgs.add(RValue::get(Receiver), ASTIdTy);
1123 ActualArgs.add(RValue::get(cmd), CGF.getContext().getObjCSelType());
1124 ActualArgs.insert(ActualArgs.end(), CallArgs.begin(), CallArgs.end());
1126 CodeGenTypes &Types = CGM.getTypes();
1127 const CGFunctionInfo &FnInfo = Types.getFunctionInfo(ResultType, ActualArgs,
1128 FunctionType::ExtInfo());
1129 const llvm::FunctionType *impType =
1130 Types.GetFunctionType(FnInfo, Method ? Method->isVariadic() : false);
1131 imp = EnforceType(Builder, imp, llvm::PointerType::getUnqual(impType));
1134 // For sender-aware dispatch, we pass the sender as the third argument to a
1135 // lookup function. When sending messages from C code, the sender is nil.
1136 // objc_msg_lookup_sender(id *receiver, SEL selector, id sender);
1137 llvm::Instruction *call;
1138 RValue msgRet = CGF.EmitCall(FnInfo, imp, Return, ActualArgs,
1140 call->setMetadata(msgSendMDKind, node);
1143 if (!isPointerSizedReturn) {
1144 messageBB = CGF.Builder.GetInsertBlock();
1145 CGF.Builder.CreateBr(continueBB);
1146 CGF.EmitBlock(continueBB);
1147 if (msgRet.isScalar()) {
1148 llvm::Value *v = msgRet.getScalarVal();
1149 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2);
1150 phi->addIncoming(v, messageBB);
1151 phi->addIncoming(llvm::Constant::getNullValue(v->getType()), startBB);
1152 msgRet = RValue::get(phi);
1153 } else if (msgRet.isAggregate()) {
1154 llvm::Value *v = msgRet.getAggregateAddr();
1155 llvm::PHINode *phi = Builder.CreatePHI(v->getType(), 2);
1156 const llvm::PointerType *RetTy = cast<llvm::PointerType>(v->getType());
1157 llvm::AllocaInst *NullVal =
1158 CGF.CreateTempAlloca(RetTy->getElementType(), "null");
1159 CGF.InitTempAlloca(NullVal,
1160 llvm::Constant::getNullValue(RetTy->getElementType()));
1161 phi->addIncoming(v, messageBB);
1162 phi->addIncoming(NullVal, startBB);
1163 msgRet = RValue::getAggregate(phi);
1164 } else /* isComplex() */ {
1165 std::pair<llvm::Value*,llvm::Value*> v = msgRet.getComplexVal();
1166 llvm::PHINode *phi = Builder.CreatePHI(v.first->getType(), 2);
1167 phi->addIncoming(v.first, messageBB);
1168 phi->addIncoming(llvm::Constant::getNullValue(v.first->getType()),
1170 llvm::PHINode *phi2 = Builder.CreatePHI(v.second->getType(), 2);
1171 phi2->addIncoming(v.second, messageBB);
1172 phi2->addIncoming(llvm::Constant::getNullValue(v.second->getType()),
1174 msgRet = RValue::getComplex(phi, phi2);
1180 /// Generates a MethodList. Used in construction of a objc_class and
1181 /// objc_category structures.
1182 llvm::Constant *CGObjCGNU::GenerateMethodList(const llvm::StringRef &ClassName,
1183 const llvm::StringRef &CategoryName,
1184 const llvm::SmallVectorImpl<Selector> &MethodSels,
1185 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes,
1186 bool isClassMethodList) {
1187 if (MethodSels.empty())
1189 // Get the method structure type.
1190 llvm::StructType *ObjCMethodTy = llvm::StructType::get(VMContext,
1191 PtrToInt8Ty, // Really a selector, but the runtime creates it us.
1192 PtrToInt8Ty, // Method types
1193 IMPTy, //Method pointer
1195 std::vector<llvm::Constant*> Methods;
1196 std::vector<llvm::Constant*> Elements;
1197 for (unsigned int i = 0, e = MethodTypes.size(); i < e; ++i) {
1199 llvm::Constant *Method =
1200 TheModule.getFunction(SymbolNameForMethod(ClassName, CategoryName,
1202 isClassMethodList));
1203 assert(Method && "Can't generate metadata for method that doesn't exist");
1204 llvm::Constant *C = MakeConstantString(MethodSels[i].getAsString());
1205 Elements.push_back(C);
1206 Elements.push_back(MethodTypes[i]);
1207 Method = llvm::ConstantExpr::getBitCast(Method,
1209 Elements.push_back(Method);
1210 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodTy, Elements));
1213 // Array of method structures
1214 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodTy,
1216 llvm::Constant *MethodArray = llvm::ConstantArray::get(ObjCMethodArrayTy,
1219 // Structure containing list pointer, array and array count
1220 llvm::SmallVector<const llvm::Type*, 16> ObjCMethodListFields;
1221 llvm::PATypeHolder OpaqueNextTy = llvm::OpaqueType::get(VMContext);
1222 llvm::Type *NextPtrTy = llvm::PointerType::getUnqual(OpaqueNextTy);
1223 llvm::StructType *ObjCMethodListTy = llvm::StructType::get(VMContext,
1228 // Refine next pointer type to concrete type
1229 llvm::cast<llvm::OpaqueType>(
1230 OpaqueNextTy.get())->refineAbstractTypeTo(ObjCMethodListTy);
1231 ObjCMethodListTy = llvm::cast<llvm::StructType>(OpaqueNextTy.get());
1234 Methods.push_back(llvm::ConstantPointerNull::get(
1235 llvm::PointerType::getUnqual(ObjCMethodListTy)));
1236 Methods.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
1237 MethodTypes.size()));
1238 Methods.push_back(MethodArray);
1240 // Create an instance of the structure
1241 return MakeGlobal(ObjCMethodListTy, Methods, ".objc_method_list");
1244 /// Generates an IvarList. Used in construction of a objc_class.
1245 llvm::Constant *CGObjCGNU::GenerateIvarList(
1246 const llvm::SmallVectorImpl<llvm::Constant *> &IvarNames,
1247 const llvm::SmallVectorImpl<llvm::Constant *> &IvarTypes,
1248 const llvm::SmallVectorImpl<llvm::Constant *> &IvarOffsets) {
1249 if (IvarNames.size() == 0)
1251 // Get the method structure type.
1252 llvm::StructType *ObjCIvarTy = llvm::StructType::get(VMContext,
1257 std::vector<llvm::Constant*> Ivars;
1258 std::vector<llvm::Constant*> Elements;
1259 for (unsigned int i = 0, e = IvarNames.size() ; i < e ; i++) {
1261 Elements.push_back(IvarNames[i]);
1262 Elements.push_back(IvarTypes[i]);
1263 Elements.push_back(IvarOffsets[i]);
1264 Ivars.push_back(llvm::ConstantStruct::get(ObjCIvarTy, Elements));
1267 // Array of method structures
1268 llvm::ArrayType *ObjCIvarArrayTy = llvm::ArrayType::get(ObjCIvarTy,
1273 Elements.push_back(llvm::ConstantInt::get(IntTy, (int)IvarNames.size()));
1274 Elements.push_back(llvm::ConstantArray::get(ObjCIvarArrayTy, Ivars));
1275 // Structure containing array and array count
1276 llvm::StructType *ObjCIvarListTy = llvm::StructType::get(VMContext, IntTy,
1280 // Create an instance of the structure
1281 return MakeGlobal(ObjCIvarListTy, Elements, ".objc_ivar_list");
1284 /// Generate a class structure
1285 llvm::Constant *CGObjCGNU::GenerateClassStructure(
1286 llvm::Constant *MetaClass,
1287 llvm::Constant *SuperClass,
1290 llvm::Constant *Version,
1291 llvm::Constant *InstanceSize,
1292 llvm::Constant *IVars,
1293 llvm::Constant *Methods,
1294 llvm::Constant *Protocols,
1295 llvm::Constant *IvarOffsets,
1296 llvm::Constant *Properties,
1298 // Set up the class structure
1299 // Note: Several of these are char*s when they should be ids. This is
1300 // because the runtime performs this translation on load.
1302 // Fields marked New ABI are part of the GNUstep runtime. We emit them
1303 // anyway; the classes will still work with the GNU runtime, they will just
1305 llvm::StructType *ClassTy = llvm::StructType::get(VMContext,
1306 PtrToInt8Ty, // class_pointer
1307 PtrToInt8Ty, // super_class
1308 PtrToInt8Ty, // name
1311 LongTy, // instance_size
1312 IVars->getType(), // ivars
1313 Methods->getType(), // methods
1314 // These are all filled in by the runtime, so we pretend
1316 PtrTy, // subclass_list
1317 PtrTy, // sibling_class
1319 PtrTy, // gc_object_type
1321 LongTy, // abi_version
1322 IvarOffsets->getType(), // ivar_offsets
1323 Properties->getType(), // properties
1325 llvm::Constant *Zero = llvm::ConstantInt::get(LongTy, 0);
1326 // Fill in the structure
1327 std::vector<llvm::Constant*> Elements;
1328 Elements.push_back(llvm::ConstantExpr::getBitCast(MetaClass, PtrToInt8Ty));
1329 Elements.push_back(SuperClass);
1330 Elements.push_back(MakeConstantString(Name, ".class_name"));
1331 Elements.push_back(Zero);
1332 Elements.push_back(llvm::ConstantInt::get(LongTy, info));
1334 llvm::TargetData td(&TheModule);
1336 llvm::ConstantInt::get(LongTy,
1337 td.getTypeSizeInBits(ClassTy) /
1338 CGM.getContext().getCharWidth()));
1340 Elements.push_back(InstanceSize);
1341 Elements.push_back(IVars);
1342 Elements.push_back(Methods);
1343 Elements.push_back(NULLPtr);
1344 Elements.push_back(NULLPtr);
1345 Elements.push_back(NULLPtr);
1346 Elements.push_back(llvm::ConstantExpr::getBitCast(Protocols, PtrTy));
1347 Elements.push_back(NULLPtr);
1348 Elements.push_back(Zero);
1349 Elements.push_back(IvarOffsets);
1350 Elements.push_back(Properties);
1351 // Create an instance of the structure
1352 // This is now an externally visible symbol, so that we can speed up class
1353 // messages in the next ABI.
1354 return MakeGlobal(ClassTy, Elements, (isMeta ? "_OBJC_METACLASS_":
1355 "_OBJC_CLASS_") + std::string(Name), llvm::GlobalValue::ExternalLinkage);
1358 llvm::Constant *CGObjCGNU::GenerateProtocolMethodList(
1359 const llvm::SmallVectorImpl<llvm::Constant *> &MethodNames,
1360 const llvm::SmallVectorImpl<llvm::Constant *> &MethodTypes) {
1361 // Get the method structure type.
1362 llvm::StructType *ObjCMethodDescTy = llvm::StructType::get(VMContext,
1363 PtrToInt8Ty, // Really a selector, but the runtime does the casting for us.
1366 std::vector<llvm::Constant*> Methods;
1367 std::vector<llvm::Constant*> Elements;
1368 for (unsigned int i = 0, e = MethodTypes.size() ; i < e ; i++) {
1370 Elements.push_back(MethodNames[i]);
1371 Elements.push_back(MethodTypes[i]);
1372 Methods.push_back(llvm::ConstantStruct::get(ObjCMethodDescTy, Elements));
1374 llvm::ArrayType *ObjCMethodArrayTy = llvm::ArrayType::get(ObjCMethodDescTy,
1375 MethodNames.size());
1376 llvm::Constant *Array = llvm::ConstantArray::get(ObjCMethodArrayTy,
1378 llvm::StructType *ObjCMethodDescListTy = llvm::StructType::get(VMContext,
1379 IntTy, ObjCMethodArrayTy, NULL);
1381 Methods.push_back(llvm::ConstantInt::get(IntTy, MethodNames.size()));
1382 Methods.push_back(Array);
1383 return MakeGlobal(ObjCMethodDescListTy, Methods, ".objc_method_list");
1386 // Create the protocol list structure used in classes, categories and so on
1387 llvm::Constant *CGObjCGNU::GenerateProtocolList(
1388 const llvm::SmallVectorImpl<std::string> &Protocols) {
1389 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrToInt8Ty,
1391 llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext,
1392 PtrTy, //Should be a recurisve pointer, but it's always NULL here.
1396 std::vector<llvm::Constant*> Elements;
1397 for (const std::string *iter = Protocols.begin(), *endIter = Protocols.end();
1398 iter != endIter ; iter++) {
1399 llvm::Constant *protocol = 0;
1400 llvm::StringMap<llvm::Constant*>::iterator value =
1401 ExistingProtocols.find(*iter);
1402 if (value == ExistingProtocols.end()) {
1403 protocol = GenerateEmptyProtocol(*iter);
1405 protocol = value->getValue();
1407 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(protocol,
1409 Elements.push_back(Ptr);
1411 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy,
1414 Elements.push_back(NULLPtr);
1415 Elements.push_back(llvm::ConstantInt::get(LongTy, Protocols.size()));
1416 Elements.push_back(ProtocolArray);
1417 return MakeGlobal(ProtocolListTy, Elements, ".objc_protocol_list");
1420 llvm::Value *CGObjCGNU::GenerateProtocolRef(CGBuilderTy &Builder,
1421 const ObjCProtocolDecl *PD) {
1422 llvm::Value *protocol = ExistingProtocols[PD->getNameAsString()];
1423 const llvm::Type *T =
1424 CGM.getTypes().ConvertType(CGM.getContext().getObjCProtoType());
1425 return Builder.CreateBitCast(protocol, llvm::PointerType::getUnqual(T));
1428 llvm::Constant *CGObjCGNU::GenerateEmptyProtocol(
1429 const std::string &ProtocolName) {
1430 llvm::SmallVector<std::string, 0> EmptyStringVector;
1431 llvm::SmallVector<llvm::Constant*, 0> EmptyConstantVector;
1433 llvm::Constant *ProtocolList = GenerateProtocolList(EmptyStringVector);
1434 llvm::Constant *MethodList =
1435 GenerateProtocolMethodList(EmptyConstantVector, EmptyConstantVector);
1436 // Protocols are objects containing lists of the methods implemented and
1437 // protocols adopted.
1438 llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy,
1440 ProtocolList->getType(),
1441 MethodList->getType(),
1442 MethodList->getType(),
1443 MethodList->getType(),
1444 MethodList->getType(),
1446 std::vector<llvm::Constant*> Elements;
1447 // The isa pointer must be set to a magic number so the runtime knows it's
1448 // the correct layout.
1449 Elements.push_back(llvm::ConstantExpr::getIntToPtr(
1450 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
1451 ProtocolVersion), IdTy));
1452 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name"));
1453 Elements.push_back(ProtocolList);
1454 Elements.push_back(MethodList);
1455 Elements.push_back(MethodList);
1456 Elements.push_back(MethodList);
1457 Elements.push_back(MethodList);
1458 return MakeGlobal(ProtocolTy, Elements, ".objc_protocol");
1461 void CGObjCGNU::GenerateProtocol(const ObjCProtocolDecl *PD) {
1462 ASTContext &Context = CGM.getContext();
1463 std::string ProtocolName = PD->getNameAsString();
1464 llvm::SmallVector<std::string, 16> Protocols;
1465 for (ObjCProtocolDecl::protocol_iterator PI = PD->protocol_begin(),
1466 E = PD->protocol_end(); PI != E; ++PI)
1467 Protocols.push_back((*PI)->getNameAsString());
1468 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodNames;
1469 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
1470 llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodNames;
1471 llvm::SmallVector<llvm::Constant*, 16> OptionalInstanceMethodTypes;
1472 for (ObjCProtocolDecl::instmeth_iterator iter = PD->instmeth_begin(),
1473 E = PD->instmeth_end(); iter != E; iter++) {
1474 std::string TypeStr;
1475 Context.getObjCEncodingForMethodDecl(*iter, TypeStr);
1476 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) {
1477 InstanceMethodNames.push_back(
1478 MakeConstantString((*iter)->getSelector().getAsString()));
1479 InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
1481 OptionalInstanceMethodNames.push_back(
1482 MakeConstantString((*iter)->getSelector().getAsString()));
1483 OptionalInstanceMethodTypes.push_back(MakeConstantString(TypeStr));
1486 // Collect information about class methods:
1487 llvm::SmallVector<llvm::Constant*, 16> ClassMethodNames;
1488 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes;
1489 llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodNames;
1490 llvm::SmallVector<llvm::Constant*, 16> OptionalClassMethodTypes;
1491 for (ObjCProtocolDecl::classmeth_iterator
1492 iter = PD->classmeth_begin(), endIter = PD->classmeth_end();
1493 iter != endIter ; iter++) {
1494 std::string TypeStr;
1495 Context.getObjCEncodingForMethodDecl((*iter),TypeStr);
1496 if ((*iter)->getImplementationControl() == ObjCMethodDecl::Optional) {
1497 ClassMethodNames.push_back(
1498 MakeConstantString((*iter)->getSelector().getAsString()));
1499 ClassMethodTypes.push_back(MakeConstantString(TypeStr));
1501 OptionalClassMethodNames.push_back(
1502 MakeConstantString((*iter)->getSelector().getAsString()));
1503 OptionalClassMethodTypes.push_back(MakeConstantString(TypeStr));
1507 llvm::Constant *ProtocolList = GenerateProtocolList(Protocols);
1508 llvm::Constant *InstanceMethodList =
1509 GenerateProtocolMethodList(InstanceMethodNames, InstanceMethodTypes);
1510 llvm::Constant *ClassMethodList =
1511 GenerateProtocolMethodList(ClassMethodNames, ClassMethodTypes);
1512 llvm::Constant *OptionalInstanceMethodList =
1513 GenerateProtocolMethodList(OptionalInstanceMethodNames,
1514 OptionalInstanceMethodTypes);
1515 llvm::Constant *OptionalClassMethodList =
1516 GenerateProtocolMethodList(OptionalClassMethodNames,
1517 OptionalClassMethodTypes);
1519 // Property metadata: name, attributes, isSynthesized, setter name, setter
1520 // types, getter name, getter types.
1521 // The isSynthesized value is always set to 0 in a protocol. It exists to
1522 // simplify the runtime library by allowing it to use the same data
1523 // structures for protocol metadata everywhere.
1524 llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext,
1525 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty,
1527 std::vector<llvm::Constant*> Properties;
1528 std::vector<llvm::Constant*> OptionalProperties;
1530 // Add all of the property methods need adding to the method list and to the
1531 // property metadata list.
1532 for (ObjCContainerDecl::prop_iterator
1533 iter = PD->prop_begin(), endIter = PD->prop_end();
1534 iter != endIter ; iter++) {
1535 std::vector<llvm::Constant*> Fields;
1536 ObjCPropertyDecl *property = (*iter);
1538 Fields.push_back(MakeConstantString(property->getNameAsString()));
1539 Fields.push_back(llvm::ConstantInt::get(Int8Ty,
1540 property->getPropertyAttributes()));
1541 Fields.push_back(llvm::ConstantInt::get(Int8Ty, 0));
1542 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) {
1543 std::string TypeStr;
1544 Context.getObjCEncodingForMethodDecl(getter,TypeStr);
1545 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
1546 InstanceMethodTypes.push_back(TypeEncoding);
1547 Fields.push_back(MakeConstantString(getter->getSelector().getAsString()));
1548 Fields.push_back(TypeEncoding);
1550 Fields.push_back(NULLPtr);
1551 Fields.push_back(NULLPtr);
1553 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) {
1554 std::string TypeStr;
1555 Context.getObjCEncodingForMethodDecl(setter,TypeStr);
1556 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
1557 InstanceMethodTypes.push_back(TypeEncoding);
1558 Fields.push_back(MakeConstantString(setter->getSelector().getAsString()));
1559 Fields.push_back(TypeEncoding);
1561 Fields.push_back(NULLPtr);
1562 Fields.push_back(NULLPtr);
1564 if (property->getPropertyImplementation() == ObjCPropertyDecl::Optional) {
1565 OptionalProperties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields));
1567 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields));
1570 llvm::Constant *PropertyArray = llvm::ConstantArray::get(
1571 llvm::ArrayType::get(PropertyMetadataTy, Properties.size()), Properties);
1572 llvm::Constant* PropertyListInitFields[] =
1573 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray};
1575 llvm::Constant *PropertyListInit =
1576 llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false);
1577 llvm::Constant *PropertyList = new llvm::GlobalVariable(TheModule,
1578 PropertyListInit->getType(), false, llvm::GlobalValue::InternalLinkage,
1579 PropertyListInit, ".objc_property_list");
1581 llvm::Constant *OptionalPropertyArray =
1582 llvm::ConstantArray::get(llvm::ArrayType::get(PropertyMetadataTy,
1583 OptionalProperties.size()) , OptionalProperties);
1584 llvm::Constant* OptionalPropertyListInitFields[] = {
1585 llvm::ConstantInt::get(IntTy, OptionalProperties.size()), NULLPtr,
1586 OptionalPropertyArray };
1588 llvm::Constant *OptionalPropertyListInit =
1589 llvm::ConstantStruct::get(VMContext, OptionalPropertyListInitFields, 3, false);
1590 llvm::Constant *OptionalPropertyList = new llvm::GlobalVariable(TheModule,
1591 OptionalPropertyListInit->getType(), false,
1592 llvm::GlobalValue::InternalLinkage, OptionalPropertyListInit,
1593 ".objc_property_list");
1595 // Protocols are objects containing lists of the methods implemented and
1596 // protocols adopted.
1597 llvm::StructType *ProtocolTy = llvm::StructType::get(VMContext, IdTy,
1599 ProtocolList->getType(),
1600 InstanceMethodList->getType(),
1601 ClassMethodList->getType(),
1602 OptionalInstanceMethodList->getType(),
1603 OptionalClassMethodList->getType(),
1604 PropertyList->getType(),
1605 OptionalPropertyList->getType(),
1607 std::vector<llvm::Constant*> Elements;
1608 // The isa pointer must be set to a magic number so the runtime knows it's
1609 // the correct layout.
1610 Elements.push_back(llvm::ConstantExpr::getIntToPtr(
1611 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
1612 ProtocolVersion), IdTy));
1613 Elements.push_back(MakeConstantString(ProtocolName, ".objc_protocol_name"));
1614 Elements.push_back(ProtocolList);
1615 Elements.push_back(InstanceMethodList);
1616 Elements.push_back(ClassMethodList);
1617 Elements.push_back(OptionalInstanceMethodList);
1618 Elements.push_back(OptionalClassMethodList);
1619 Elements.push_back(PropertyList);
1620 Elements.push_back(OptionalPropertyList);
1621 ExistingProtocols[ProtocolName] =
1622 llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolTy, Elements,
1623 ".objc_protocol"), IdTy);
1625 void CGObjCGNU::GenerateProtocolHolderCategory(void) {
1626 // Collect information about instance methods
1627 llvm::SmallVector<Selector, 1> MethodSels;
1628 llvm::SmallVector<llvm::Constant*, 1> MethodTypes;
1630 std::vector<llvm::Constant*> Elements;
1631 const std::string ClassName = "__ObjC_Protocol_Holder_Ugly_Hack";
1632 const std::string CategoryName = "AnotherHack";
1633 Elements.push_back(MakeConstantString(CategoryName));
1634 Elements.push_back(MakeConstantString(ClassName));
1635 // Instance method list
1636 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList(
1637 ClassName, CategoryName, MethodSels, MethodTypes, false), PtrTy));
1638 // Class method list
1639 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList(
1640 ClassName, CategoryName, MethodSels, MethodTypes, true), PtrTy));
1642 llvm::ArrayType *ProtocolArrayTy = llvm::ArrayType::get(PtrTy,
1643 ExistingProtocols.size());
1644 llvm::StructType *ProtocolListTy = llvm::StructType::get(VMContext,
1645 PtrTy, //Should be a recurisve pointer, but it's always NULL here.
1649 std::vector<llvm::Constant*> ProtocolElements;
1650 for (llvm::StringMapIterator<llvm::Constant*> iter =
1651 ExistingProtocols.begin(), endIter = ExistingProtocols.end();
1652 iter != endIter ; iter++) {
1653 llvm::Constant *Ptr = llvm::ConstantExpr::getBitCast(iter->getValue(),
1655 ProtocolElements.push_back(Ptr);
1657 llvm::Constant * ProtocolArray = llvm::ConstantArray::get(ProtocolArrayTy,
1659 ProtocolElements.clear();
1660 ProtocolElements.push_back(NULLPtr);
1661 ProtocolElements.push_back(llvm::ConstantInt::get(LongTy,
1662 ExistingProtocols.size()));
1663 ProtocolElements.push_back(ProtocolArray);
1664 Elements.push_back(llvm::ConstantExpr::getBitCast(MakeGlobal(ProtocolListTy,
1665 ProtocolElements, ".objc_protocol_list"), PtrTy));
1666 Categories.push_back(llvm::ConstantExpr::getBitCast(
1667 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty,
1668 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy));
1671 void CGObjCGNU::GenerateCategory(const ObjCCategoryImplDecl *OCD) {
1672 std::string ClassName = OCD->getClassInterface()->getNameAsString();
1673 std::string CategoryName = OCD->getNameAsString();
1674 // Collect information about instance methods
1675 llvm::SmallVector<Selector, 16> InstanceMethodSels;
1676 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
1677 for (ObjCCategoryImplDecl::instmeth_iterator
1678 iter = OCD->instmeth_begin(), endIter = OCD->instmeth_end();
1679 iter != endIter ; iter++) {
1680 InstanceMethodSels.push_back((*iter)->getSelector());
1681 std::string TypeStr;
1682 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr);
1683 InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
1686 // Collect information about class methods
1687 llvm::SmallVector<Selector, 16> ClassMethodSels;
1688 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes;
1689 for (ObjCCategoryImplDecl::classmeth_iterator
1690 iter = OCD->classmeth_begin(), endIter = OCD->classmeth_end();
1691 iter != endIter ; iter++) {
1692 ClassMethodSels.push_back((*iter)->getSelector());
1693 std::string TypeStr;
1694 CGM.getContext().getObjCEncodingForMethodDecl(*iter,TypeStr);
1695 ClassMethodTypes.push_back(MakeConstantString(TypeStr));
1698 // Collect the names of referenced protocols
1699 llvm::SmallVector<std::string, 16> Protocols;
1700 const ObjCCategoryDecl *CatDecl = OCD->getCategoryDecl();
1701 const ObjCList<ObjCProtocolDecl> &Protos = CatDecl->getReferencedProtocols();
1702 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(),
1703 E = Protos.end(); I != E; ++I)
1704 Protocols.push_back((*I)->getNameAsString());
1706 std::vector<llvm::Constant*> Elements;
1707 Elements.push_back(MakeConstantString(CategoryName));
1708 Elements.push_back(MakeConstantString(ClassName));
1709 // Instance method list
1710 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList(
1711 ClassName, CategoryName, InstanceMethodSels, InstanceMethodTypes,
1713 // Class method list
1714 Elements.push_back(llvm::ConstantExpr::getBitCast(GenerateMethodList(
1715 ClassName, CategoryName, ClassMethodSels, ClassMethodTypes, true),
1718 Elements.push_back(llvm::ConstantExpr::getBitCast(
1719 GenerateProtocolList(Protocols), PtrTy));
1720 Categories.push_back(llvm::ConstantExpr::getBitCast(
1721 MakeGlobal(llvm::StructType::get(VMContext, PtrToInt8Ty, PtrToInt8Ty,
1722 PtrTy, PtrTy, PtrTy, NULL), Elements), PtrTy));
1725 llvm::Constant *CGObjCGNU::GeneratePropertyList(const ObjCImplementationDecl *OID,
1726 llvm::SmallVectorImpl<Selector> &InstanceMethodSels,
1727 llvm::SmallVectorImpl<llvm::Constant*> &InstanceMethodTypes) {
1728 ASTContext &Context = CGM.getContext();
1730 // Property metadata: name, attributes, isSynthesized, setter name, setter
1731 // types, getter name, getter types.
1732 llvm::StructType *PropertyMetadataTy = llvm::StructType::get(VMContext,
1733 PtrToInt8Ty, Int8Ty, Int8Ty, PtrToInt8Ty, PtrToInt8Ty, PtrToInt8Ty,
1735 std::vector<llvm::Constant*> Properties;
1738 // Add all of the property methods need adding to the method list and to the
1739 // property metadata list.
1740 for (ObjCImplDecl::propimpl_iterator
1741 iter = OID->propimpl_begin(), endIter = OID->propimpl_end();
1742 iter != endIter ; iter++) {
1743 std::vector<llvm::Constant*> Fields;
1744 ObjCPropertyDecl *property = (*iter)->getPropertyDecl();
1745 ObjCPropertyImplDecl *propertyImpl = *iter;
1746 bool isSynthesized = (propertyImpl->getPropertyImplementation() ==
1747 ObjCPropertyImplDecl::Synthesize);
1749 Fields.push_back(MakeConstantString(property->getNameAsString()));
1750 Fields.push_back(llvm::ConstantInt::get(Int8Ty,
1751 property->getPropertyAttributes()));
1752 Fields.push_back(llvm::ConstantInt::get(Int8Ty, isSynthesized));
1753 if (ObjCMethodDecl *getter = property->getGetterMethodDecl()) {
1754 std::string TypeStr;
1755 Context.getObjCEncodingForMethodDecl(getter,TypeStr);
1756 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
1757 if (isSynthesized) {
1758 InstanceMethodTypes.push_back(TypeEncoding);
1759 InstanceMethodSels.push_back(getter->getSelector());
1761 Fields.push_back(MakeConstantString(getter->getSelector().getAsString()));
1762 Fields.push_back(TypeEncoding);
1764 Fields.push_back(NULLPtr);
1765 Fields.push_back(NULLPtr);
1767 if (ObjCMethodDecl *setter = property->getSetterMethodDecl()) {
1768 std::string TypeStr;
1769 Context.getObjCEncodingForMethodDecl(setter,TypeStr);
1770 llvm::Constant *TypeEncoding = MakeConstantString(TypeStr);
1771 if (isSynthesized) {
1772 InstanceMethodTypes.push_back(TypeEncoding);
1773 InstanceMethodSels.push_back(setter->getSelector());
1775 Fields.push_back(MakeConstantString(setter->getSelector().getAsString()));
1776 Fields.push_back(TypeEncoding);
1778 Fields.push_back(NULLPtr);
1779 Fields.push_back(NULLPtr);
1781 Properties.push_back(llvm::ConstantStruct::get(PropertyMetadataTy, Fields));
1783 llvm::ArrayType *PropertyArrayTy =
1784 llvm::ArrayType::get(PropertyMetadataTy, Properties.size());
1785 llvm::Constant *PropertyArray = llvm::ConstantArray::get(PropertyArrayTy,
1787 llvm::Constant* PropertyListInitFields[] =
1788 {llvm::ConstantInt::get(IntTy, Properties.size()), NULLPtr, PropertyArray};
1790 llvm::Constant *PropertyListInit =
1791 llvm::ConstantStruct::get(VMContext, PropertyListInitFields, 3, false);
1792 return new llvm::GlobalVariable(TheModule, PropertyListInit->getType(), false,
1793 llvm::GlobalValue::InternalLinkage, PropertyListInit,
1794 ".objc_property_list");
1797 void CGObjCGNU::GenerateClass(const ObjCImplementationDecl *OID) {
1798 ASTContext &Context = CGM.getContext();
1800 // Get the superclass name.
1801 const ObjCInterfaceDecl * SuperClassDecl =
1802 OID->getClassInterface()->getSuperClass();
1803 std::string SuperClassName;
1804 if (SuperClassDecl) {
1805 SuperClassName = SuperClassDecl->getNameAsString();
1806 EmitClassRef(SuperClassName);
1809 // Get the class name
1810 ObjCInterfaceDecl *ClassDecl =
1811 const_cast<ObjCInterfaceDecl *>(OID->getClassInterface());
1812 std::string ClassName = ClassDecl->getNameAsString();
1813 // Emit the symbol that is used to generate linker errors if this class is
1814 // referenced in other modules but not declared.
1815 std::string classSymbolName = "__objc_class_name_" + ClassName;
1816 if (llvm::GlobalVariable *symbol =
1817 TheModule.getGlobalVariable(classSymbolName)) {
1818 symbol->setInitializer(llvm::ConstantInt::get(LongTy, 0));
1820 new llvm::GlobalVariable(TheModule, LongTy, false,
1821 llvm::GlobalValue::ExternalLinkage, llvm::ConstantInt::get(LongTy, 0),
1825 // Get the size of instances.
1827 Context.getASTObjCImplementationLayout(OID).getSize().getQuantity();
1829 // Collect information about instance variables.
1830 llvm::SmallVector<llvm::Constant*, 16> IvarNames;
1831 llvm::SmallVector<llvm::Constant*, 16> IvarTypes;
1832 llvm::SmallVector<llvm::Constant*, 16> IvarOffsets;
1834 std::vector<llvm::Constant*> IvarOffsetValues;
1836 int superInstanceSize = !SuperClassDecl ? 0 :
1837 Context.getASTObjCInterfaceLayout(SuperClassDecl).getSize().getQuantity();
1838 // For non-fragile ivars, set the instance size to 0 - {the size of just this
1839 // class}. The runtime will then set this to the correct value on load.
1840 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) {
1841 instanceSize = 0 - (instanceSize - superInstanceSize);
1844 // Collect declared and synthesized ivars.
1845 llvm::SmallVector<ObjCIvarDecl*, 16> OIvars;
1846 CGM.getContext().ShallowCollectObjCIvars(ClassDecl, OIvars);
1848 for (unsigned i = 0, e = OIvars.size(); i != e; ++i) {
1849 ObjCIvarDecl *IVD = OIvars[i];
1851 IvarNames.push_back(MakeConstantString(IVD->getNameAsString()));
1852 // Get the type encoding for this ivar
1853 std::string TypeStr;
1854 Context.getObjCEncodingForType(IVD->getType(), TypeStr);
1855 IvarTypes.push_back(MakeConstantString(TypeStr));
1857 uint64_t BaseOffset = ComputeIvarBaseOffset(CGM, OID, IVD);
1858 uint64_t Offset = BaseOffset;
1859 if (CGM.getContext().getLangOptions().ObjCNonFragileABI) {
1860 Offset = BaseOffset - superInstanceSize;
1862 IvarOffsets.push_back(
1863 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset));
1864 IvarOffsetValues.push_back(new llvm::GlobalVariable(TheModule, IntTy,
1865 false, llvm::GlobalValue::ExternalLinkage,
1866 llvm::ConstantInt::get(IntTy, Offset),
1867 "__objc_ivar_offset_value_" + ClassName +"." +
1868 IVD->getNameAsString()));
1870 llvm::GlobalVariable *IvarOffsetArray =
1871 MakeGlobalArray(PtrToIntTy, IvarOffsetValues, ".ivar.offsets");
1874 // Collect information about instance methods
1875 llvm::SmallVector<Selector, 16> InstanceMethodSels;
1876 llvm::SmallVector<llvm::Constant*, 16> InstanceMethodTypes;
1877 for (ObjCImplementationDecl::instmeth_iterator
1878 iter = OID->instmeth_begin(), endIter = OID->instmeth_end();
1879 iter != endIter ; iter++) {
1880 InstanceMethodSels.push_back((*iter)->getSelector());
1881 std::string TypeStr;
1882 Context.getObjCEncodingForMethodDecl((*iter),TypeStr);
1883 InstanceMethodTypes.push_back(MakeConstantString(TypeStr));
1886 llvm::Constant *Properties = GeneratePropertyList(OID, InstanceMethodSels,
1887 InstanceMethodTypes);
1890 // Collect information about class methods
1891 llvm::SmallVector<Selector, 16> ClassMethodSels;
1892 llvm::SmallVector<llvm::Constant*, 16> ClassMethodTypes;
1893 for (ObjCImplementationDecl::classmeth_iterator
1894 iter = OID->classmeth_begin(), endIter = OID->classmeth_end();
1895 iter != endIter ; iter++) {
1896 ClassMethodSels.push_back((*iter)->getSelector());
1897 std::string TypeStr;
1898 Context.getObjCEncodingForMethodDecl((*iter),TypeStr);
1899 ClassMethodTypes.push_back(MakeConstantString(TypeStr));
1901 // Collect the names of referenced protocols
1902 llvm::SmallVector<std::string, 16> Protocols;
1903 const ObjCList<ObjCProtocolDecl> &Protos =ClassDecl->getReferencedProtocols();
1904 for (ObjCList<ObjCProtocolDecl>::iterator I = Protos.begin(),
1905 E = Protos.end(); I != E; ++I)
1906 Protocols.push_back((*I)->getNameAsString());
1910 // Get the superclass pointer.
1911 llvm::Constant *SuperClass;
1912 if (!SuperClassName.empty()) {
1913 SuperClass = MakeConstantString(SuperClassName, ".super_class_name");
1915 SuperClass = llvm::ConstantPointerNull::get(PtrToInt8Ty);
1917 // Empty vector used to construct empty method lists
1918 llvm::SmallVector<llvm::Constant*, 1> empty;
1919 // Generate the method and instance variable lists
1920 llvm::Constant *MethodList = GenerateMethodList(ClassName, "",
1921 InstanceMethodSels, InstanceMethodTypes, false);
1922 llvm::Constant *ClassMethodList = GenerateMethodList(ClassName, "",
1923 ClassMethodSels, ClassMethodTypes, true);
1924 llvm::Constant *IvarList = GenerateIvarList(IvarNames, IvarTypes,
1926 // Irrespective of whether we are compiling for a fragile or non-fragile ABI,
1927 // we emit a symbol containing the offset for each ivar in the class. This
1928 // allows code compiled for the non-Fragile ABI to inherit from code compiled
1929 // for the legacy ABI, without causing problems. The converse is also
1930 // possible, but causes all ivar accesses to be fragile.
1932 // Offset pointer for getting at the correct field in the ivar list when
1933 // setting up the alias. These are: The base address for the global, the
1934 // ivar array (second field), the ivar in this list (set for each ivar), and
1935 // the offset (third field in ivar structure)
1936 const llvm::Type *IndexTy = llvm::Type::getInt32Ty(VMContext);
1937 llvm::Constant *offsetPointerIndexes[] = {Zeros[0],
1938 llvm::ConstantInt::get(IndexTy, 1), 0,
1939 llvm::ConstantInt::get(IndexTy, 2) };
1942 for (unsigned i = 0, e = OIvars.size(); i != e; ++i) {
1943 ObjCIvarDecl *IVD = OIvars[i];
1944 const std::string Name = "__objc_ivar_offset_" + ClassName + '.'
1945 + IVD->getNameAsString();
1946 offsetPointerIndexes[2] = llvm::ConstantInt::get(IndexTy, i);
1947 // Get the correct ivar field
1948 llvm::Constant *offsetValue = llvm::ConstantExpr::getGetElementPtr(
1949 IvarList, offsetPointerIndexes, 4);
1950 // Get the existing variable, if one exists.
1951 llvm::GlobalVariable *offset = TheModule.getNamedGlobal(Name);
1953 offset->setInitializer(offsetValue);
1954 // If this is the real definition, change its linkage type so that
1955 // different modules will use this one, rather than their private
1957 offset->setLinkage(llvm::GlobalValue::ExternalLinkage);
1959 // Add a new alias if there isn't one already.
1960 offset = new llvm::GlobalVariable(TheModule, offsetValue->getType(),
1961 false, llvm::GlobalValue::ExternalLinkage, offsetValue, Name);
1964 //Generate metaclass for class methods
1965 llvm::Constant *MetaClassStruct = GenerateClassStructure(NULLPtr,
1966 NULLPtr, 0x12L, ClassName.c_str(), 0, Zeros[0], GenerateIvarList(
1967 empty, empty, empty), ClassMethodList, NULLPtr, NULLPtr, NULLPtr, true);
1969 // Generate the class structure
1970 llvm::Constant *ClassStruct =
1971 GenerateClassStructure(MetaClassStruct, SuperClass, 0x11L,
1972 ClassName.c_str(), 0,
1973 llvm::ConstantInt::get(LongTy, instanceSize), IvarList,
1974 MethodList, GenerateProtocolList(Protocols), IvarOffsetArray,
1977 // Resolve the class aliases, if they exist.
1978 if (ClassPtrAlias) {
1979 ClassPtrAlias->replaceAllUsesWith(
1980 llvm::ConstantExpr::getBitCast(ClassStruct, IdTy));
1981 ClassPtrAlias->eraseFromParent();
1984 if (MetaClassPtrAlias) {
1985 MetaClassPtrAlias->replaceAllUsesWith(
1986 llvm::ConstantExpr::getBitCast(MetaClassStruct, IdTy));
1987 MetaClassPtrAlias->eraseFromParent();
1988 MetaClassPtrAlias = 0;
1991 // Add class structure to list to be added to the symtab later
1992 ClassStruct = llvm::ConstantExpr::getBitCast(ClassStruct, PtrToInt8Ty);
1993 Classes.push_back(ClassStruct);
1997 llvm::Function *CGObjCGNU::ModuleInitFunction() {
1998 // Only emit an ObjC load function if no Objective-C stuff has been called
1999 if (Classes.empty() && Categories.empty() && ConstantStrings.empty() &&
2000 ExistingProtocols.empty() && SelectorTable.empty())
2003 // Add all referenced protocols to a category.
2004 GenerateProtocolHolderCategory();
2006 const llvm::StructType *SelStructTy = dyn_cast<llvm::StructType>(
2007 SelectorTy->getElementType());
2008 const llvm::Type *SelStructPtrTy = SelectorTy;
2009 if (SelStructTy == 0) {
2010 SelStructTy = llvm::StructType::get(VMContext, PtrToInt8Ty,
2012 SelStructPtrTy = llvm::PointerType::getUnqual(SelStructTy);
2015 // Name the ObjC types to make the IR a bit easier to read
2016 TheModule.addTypeName(".objc_selector", SelStructPtrTy);
2017 TheModule.addTypeName(".objc_id", IdTy);
2018 TheModule.addTypeName(".objc_imp", IMPTy);
2020 std::vector<llvm::Constant*> Elements;
2021 llvm::Constant *Statics = NULLPtr;
2022 // Generate statics list:
2023 if (ConstantStrings.size()) {
2024 llvm::ArrayType *StaticsArrayTy = llvm::ArrayType::get(PtrToInt8Ty,
2025 ConstantStrings.size() + 1);
2026 ConstantStrings.push_back(NULLPtr);
2028 llvm::StringRef StringClass = CGM.getLangOptions().ObjCConstantStringClass;
2030 if (StringClass.empty()) StringClass = "NXConstantString";
2032 Elements.push_back(MakeConstantString(StringClass,
2033 ".objc_static_class_name"));
2034 Elements.push_back(llvm::ConstantArray::get(StaticsArrayTy,
2036 llvm::StructType *StaticsListTy =
2037 llvm::StructType::get(VMContext, PtrToInt8Ty, StaticsArrayTy, NULL);
2038 llvm::Type *StaticsListPtrTy =
2039 llvm::PointerType::getUnqual(StaticsListTy);
2040 Statics = MakeGlobal(StaticsListTy, Elements, ".objc_statics");
2041 llvm::ArrayType *StaticsListArrayTy =
2042 llvm::ArrayType::get(StaticsListPtrTy, 2);
2044 Elements.push_back(Statics);
2045 Elements.push_back(llvm::Constant::getNullValue(StaticsListPtrTy));
2046 Statics = MakeGlobal(StaticsListArrayTy, Elements, ".objc_statics_ptr");
2047 Statics = llvm::ConstantExpr::getBitCast(Statics, PtrTy);
2049 // Array of classes, categories, and constant objects
2050 llvm::ArrayType *ClassListTy = llvm::ArrayType::get(PtrToInt8Ty,
2051 Classes.size() + Categories.size() + 2);
2052 llvm::StructType *SymTabTy = llvm::StructType::get(VMContext,
2053 LongTy, SelStructPtrTy,
2054 llvm::Type::getInt16Ty(VMContext),
2055 llvm::Type::getInt16Ty(VMContext),
2059 // Pointer to an array of selectors used in this module.
2060 std::vector<llvm::Constant*> Selectors;
2061 std::vector<llvm::GlobalAlias*> SelectorAliases;
2062 for (SelectorMap::iterator iter = SelectorTable.begin(),
2063 iterEnd = SelectorTable.end(); iter != iterEnd ; ++iter) {
2065 std::string SelNameStr = iter->first.getAsString();
2066 llvm::Constant *SelName = ExportUniqueString(SelNameStr, ".objc_sel_name");
2068 llvm::SmallVectorImpl<TypedSelector> &Types = iter->second;
2069 for (llvm::SmallVectorImpl<TypedSelector>::iterator i = Types.begin(),
2070 e = Types.end() ; i!=e ; i++) {
2072 llvm::Constant *SelectorTypeEncoding = NULLPtr;
2073 if (!i->first.empty())
2074 SelectorTypeEncoding = MakeConstantString(i->first, ".objc_sel_types");
2076 Elements.push_back(SelName);
2077 Elements.push_back(SelectorTypeEncoding);
2078 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements));
2081 // Store the selector alias for later replacement
2082 SelectorAliases.push_back(i->second);
2085 unsigned SelectorCount = Selectors.size();
2086 // NULL-terminate the selector list. This should not actually be required,
2087 // because the selector list has a length field. Unfortunately, the GCC
2088 // runtime decides to ignore the length field and expects a NULL terminator,
2089 // and GCC cooperates with this by always setting the length to 0.
2090 Elements.push_back(NULLPtr);
2091 Elements.push_back(NULLPtr);
2092 Selectors.push_back(llvm::ConstantStruct::get(SelStructTy, Elements));
2095 // Number of static selectors
2096 Elements.push_back(llvm::ConstantInt::get(LongTy, SelectorCount));
2097 llvm::Constant *SelectorList = MakeGlobalArray(SelStructTy, Selectors,
2098 ".objc_selector_list");
2099 Elements.push_back(llvm::ConstantExpr::getBitCast(SelectorList,
2102 // Now that all of the static selectors exist, create pointers to them.
2103 for (unsigned int i=0 ; i<SelectorCount ; i++) {
2105 llvm::Constant *Idxs[] = {Zeros[0],
2106 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), i), Zeros[0]};
2107 // FIXME: We're generating redundant loads and stores here!
2108 llvm::Constant *SelPtr = llvm::ConstantExpr::getGetElementPtr(SelectorList,
2110 // If selectors are defined as an opaque type, cast the pointer to this
2112 SelPtr = llvm::ConstantExpr::getBitCast(SelPtr, SelectorTy);
2113 SelectorAliases[i]->replaceAllUsesWith(SelPtr);
2114 SelectorAliases[i]->eraseFromParent();
2117 // Number of classes defined.
2118 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext),
2120 // Number of categories defined
2121 Elements.push_back(llvm::ConstantInt::get(llvm::Type::getInt16Ty(VMContext),
2122 Categories.size()));
2123 // Create an array of classes, then categories, then static object instances
2124 Classes.insert(Classes.end(), Categories.begin(), Categories.end());
2125 // NULL-terminated list of static object instances (mainly constant strings)
2126 Classes.push_back(Statics);
2127 Classes.push_back(NULLPtr);
2128 llvm::Constant *ClassList = llvm::ConstantArray::get(ClassListTy, Classes);
2129 Elements.push_back(ClassList);
2130 // Construct the symbol table
2131 llvm::Constant *SymTab= MakeGlobal(SymTabTy, Elements);
2133 // The symbol table is contained in a module which has some version-checking
2135 llvm::StructType * ModuleTy = llvm::StructType::get(VMContext, LongTy, LongTy,
2136 PtrToInt8Ty, llvm::PointerType::getUnqual(SymTabTy),
2137 (CGM.getLangOptions().getGCMode() == LangOptions::NonGC) ? NULL : IntTy,
2140 // Runtime version, used for ABI compatibility checking.
2141 Elements.push_back(llvm::ConstantInt::get(LongTy, RuntimeVersion));
2143 llvm::TargetData td(&TheModule);
2145 llvm::ConstantInt::get(LongTy,
2146 td.getTypeSizeInBits(ModuleTy) /
2147 CGM.getContext().getCharWidth()));
2149 // The path to the source file where this module was declared
2150 SourceManager &SM = CGM.getContext().getSourceManager();
2151 const FileEntry *mainFile = SM.getFileEntryForID(SM.getMainFileID());
2153 std::string(mainFile->getDir()->getName()) + '/' + mainFile->getName();
2154 Elements.push_back(MakeConstantString(path, ".objc_source_file_name"));
2155 Elements.push_back(SymTab);
2157 switch (CGM.getLangOptions().getGCMode()) {
2158 case LangOptions::GCOnly:
2159 Elements.push_back(llvm::ConstantInt::get(IntTy, 2));
2160 case LangOptions::NonGC:
2162 case LangOptions::HybridGC:
2163 Elements.push_back(llvm::ConstantInt::get(IntTy, 1));
2166 llvm::Value *Module = MakeGlobal(ModuleTy, Elements);
2168 // Create the load function calling the runtime entry point with the module
2170 llvm::Function * LoadFunction = llvm::Function::Create(
2171 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false),
2172 llvm::GlobalValue::InternalLinkage, ".objc_load_function",
2174 llvm::BasicBlock *EntryBB =
2175 llvm::BasicBlock::Create(VMContext, "entry", LoadFunction);
2176 CGBuilderTy Builder(VMContext);
2177 Builder.SetInsertPoint(EntryBB);
2179 llvm::FunctionType *FT =
2180 llvm::FunctionType::get(Builder.getVoidTy(),
2181 llvm::PointerType::getUnqual(ModuleTy), true);
2182 llvm::Value *Register = CGM.CreateRuntimeFunction(FT, "__objc_exec_class");
2183 Builder.CreateCall(Register, Module);
2184 Builder.CreateRetVoid();
2186 return LoadFunction;
2189 llvm::Function *CGObjCGNU::GenerateMethod(const ObjCMethodDecl *OMD,
2190 const ObjCContainerDecl *CD) {
2191 const ObjCCategoryImplDecl *OCD =
2192 dyn_cast<ObjCCategoryImplDecl>(OMD->getDeclContext());
2193 llvm::StringRef CategoryName = OCD ? OCD->getName() : "";
2194 llvm::StringRef ClassName = CD->getName();
2195 Selector MethodName = OMD->getSelector();
2196 bool isClassMethod = !OMD->isInstanceMethod();
2198 CodeGenTypes &Types = CGM.getTypes();
2199 const llvm::FunctionType *MethodTy =
2200 Types.GetFunctionType(Types.getFunctionInfo(OMD), OMD->isVariadic());
2201 std::string FunctionName = SymbolNameForMethod(ClassName, CategoryName,
2202 MethodName, isClassMethod);
2204 llvm::Function *Method
2205 = llvm::Function::Create(MethodTy,
2206 llvm::GlobalValue::InternalLinkage,
2212 llvm::Constant *CGObjCGNU::GetPropertyGetFunction() {
2213 return GetPropertyFn;
2216 llvm::Constant *CGObjCGNU::GetPropertySetFunction() {
2217 return SetPropertyFn;
2220 llvm::Constant *CGObjCGNU::GetGetStructFunction() {
2221 return GetStructPropertyFn;
2223 llvm::Constant *CGObjCGNU::GetSetStructFunction() {
2224 return SetStructPropertyFn;
2227 llvm::Constant *CGObjCGNU::EnumerationMutationFunction() {
2228 return EnumerationMutationFn;
2231 void CGObjCGNU::EmitSynchronizedStmt(CodeGenFunction &CGF,
2232 const ObjCAtSynchronizedStmt &S) {
2233 EmitAtSynchronizedStmt(CGF, S, SyncEnterFn, SyncExitFn);
2237 void CGObjCGNU::EmitTryStmt(CodeGenFunction &CGF,
2238 const ObjCAtTryStmt &S) {
2239 // Unlike the Apple non-fragile runtimes, which also uses
2240 // unwind-based zero cost exceptions, the GNU Objective C runtime's
2241 // EH support isn't a veneer over C++ EH. Instead, exception
2242 // objects are created by __objc_exception_throw and destroyed by
2243 // the personality function; this avoids the need for bracketing
2244 // catch handlers with calls to __blah_begin_catch/__blah_end_catch
2245 // (or even _Unwind_DeleteException), but probably doesn't
2246 // interoperate very well with foreign exceptions.
2248 // In Objective-C++ mode, we actually emit something equivalent to the C++
2249 // exception handler.
2250 EmitTryCatchStmt(CGF, S, EnterCatchFn, ExitCatchFn, ExceptionReThrowFn);
2254 void CGObjCGNU::EmitThrowStmt(CodeGenFunction &CGF,
2255 const ObjCAtThrowStmt &S) {
2256 llvm::Value *ExceptionAsObject;
2258 if (const Expr *ThrowExpr = S.getThrowExpr()) {
2259 llvm::Value *Exception = CGF.EmitScalarExpr(ThrowExpr);
2260 ExceptionAsObject = Exception;
2262 assert((!CGF.ObjCEHValueStack.empty() && CGF.ObjCEHValueStack.back()) &&
2263 "Unexpected rethrow outside @catch block.");
2264 ExceptionAsObject = CGF.ObjCEHValueStack.back();
2267 CGF.Builder.CreateBitCast(ExceptionAsObject, IdTy, "tmp");
2269 // Note: This may have to be an invoke, if we want to support constructs like:
2275 // This is effectively turning @throw into an incredibly-expensive goto, but
2276 // it may happen as a result of inlining followed by missed optimizations, or
2277 // as a result of stupidity.
2278 llvm::BasicBlock *UnwindBB = CGF.getInvokeDest();
2280 CGF.Builder.CreateCall(ExceptionThrowFn, ExceptionAsObject);
2281 CGF.Builder.CreateUnreachable();
2283 CGF.Builder.CreateInvoke(ExceptionThrowFn, UnwindBB, UnwindBB, &ExceptionAsObject,
2284 &ExceptionAsObject+1);
2286 // Clear the insertion point to indicate we are in unreachable code.
2287 CGF.Builder.ClearInsertionPoint();
2290 llvm::Value * CGObjCGNU::EmitObjCWeakRead(CodeGenFunction &CGF,
2291 llvm::Value *AddrWeakObj) {
2292 CGBuilderTy B = CGF.Builder;
2293 AddrWeakObj = EnforceType(B, AddrWeakObj, PtrToIdTy);
2294 return B.CreateCall(WeakReadFn, AddrWeakObj);
2297 void CGObjCGNU::EmitObjCWeakAssign(CodeGenFunction &CGF,
2298 llvm::Value *src, llvm::Value *dst) {
2299 CGBuilderTy B = CGF.Builder;
2300 src = EnforceType(B, src, IdTy);
2301 dst = EnforceType(B, dst, PtrToIdTy);
2302 B.CreateCall2(WeakAssignFn, src, dst);
2305 void CGObjCGNU::EmitObjCGlobalAssign(CodeGenFunction &CGF,
2306 llvm::Value *src, llvm::Value *dst,
2308 CGBuilderTy B = CGF.Builder;
2309 src = EnforceType(B, src, IdTy);
2310 dst = EnforceType(B, dst, PtrToIdTy);
2312 B.CreateCall2(GlobalAssignFn, src, dst);
2314 // FIXME. Add threadloca assign API
2315 assert(false && "EmitObjCGlobalAssign - Threal Local API NYI");
2318 void CGObjCGNU::EmitObjCIvarAssign(CodeGenFunction &CGF,
2319 llvm::Value *src, llvm::Value *dst,
2320 llvm::Value *ivarOffset) {
2321 CGBuilderTy B = CGF.Builder;
2322 src = EnforceType(B, src, IdTy);
2323 dst = EnforceType(B, dst, IdTy);
2324 B.CreateCall3(IvarAssignFn, src, dst, ivarOffset);
2327 void CGObjCGNU::EmitObjCStrongCastAssign(CodeGenFunction &CGF,
2328 llvm::Value *src, llvm::Value *dst) {
2329 CGBuilderTy B = CGF.Builder;
2330 src = EnforceType(B, src, IdTy);
2331 dst = EnforceType(B, dst, PtrToIdTy);
2332 B.CreateCall2(StrongCastAssignFn, src, dst);
2335 void CGObjCGNU::EmitGCMemmoveCollectable(CodeGenFunction &CGF,
2336 llvm::Value *DestPtr,
2337 llvm::Value *SrcPtr,
2338 llvm::Value *Size) {
2339 CGBuilderTy B = CGF.Builder;
2340 DestPtr = EnforceType(B, DestPtr, PtrTy);
2341 SrcPtr = EnforceType(B, SrcPtr, PtrTy);
2343 B.CreateCall3(MemMoveFn, DestPtr, SrcPtr, Size);
2346 llvm::GlobalVariable *CGObjCGNU::ObjCIvarOffsetVariable(
2347 const ObjCInterfaceDecl *ID,
2348 const ObjCIvarDecl *Ivar) {
2349 const std::string Name = "__objc_ivar_offset_" + ID->getNameAsString()
2350 + '.' + Ivar->getNameAsString();
2351 // Emit the variable and initialize it with what we think the correct value
2352 // is. This allows code compiled with non-fragile ivars to work correctly
2353 // when linked against code which isn't (most of the time).
2354 llvm::GlobalVariable *IvarOffsetPointer = TheModule.getNamedGlobal(Name);
2355 if (!IvarOffsetPointer) {
2356 // This will cause a run-time crash if we accidentally use it. A value of
2357 // 0 would seem more sensible, but will silently overwrite the isa pointer
2358 // causing a great deal of confusion.
2359 uint64_t Offset = -1;
2360 // We can't call ComputeIvarBaseOffset() here if we have the
2361 // implementation, because it will create an invalid ASTRecordLayout object
2362 // that we are then stuck with forever, so we only initialize the ivar
2363 // offset variable with a guess if we only have the interface. The
2364 // initializer will be reset later anyway, when we are generating the class
2366 if (!CGM.getContext().getObjCImplementation(
2367 const_cast<ObjCInterfaceDecl *>(ID)))
2368 Offset = ComputeIvarBaseOffset(CGM, ID, Ivar);
2370 llvm::ConstantInt *OffsetGuess =
2371 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Offset, "ivar");
2372 // Don't emit the guess in non-PIC code because the linker will not be able
2373 // to replace it with the real version for a library. In non-PIC code you
2374 // must compile with the fragile ABI if you want to use ivars from a
2375 // GCC-compiled class.
2376 if (CGM.getLangOptions().PICLevel) {
2377 llvm::GlobalVariable *IvarOffsetGV = new llvm::GlobalVariable(TheModule,
2378 llvm::Type::getInt32Ty(VMContext), false,
2379 llvm::GlobalValue::PrivateLinkage, OffsetGuess, Name+".guess");
2380 IvarOffsetPointer = new llvm::GlobalVariable(TheModule,
2381 IvarOffsetGV->getType(), false, llvm::GlobalValue::LinkOnceAnyLinkage,
2382 IvarOffsetGV, Name);
2384 IvarOffsetPointer = new llvm::GlobalVariable(TheModule,
2385 llvm::Type::getInt32PtrTy(VMContext), false,
2386 llvm::GlobalValue::ExternalLinkage, 0, Name);
2389 return IvarOffsetPointer;
2392 LValue CGObjCGNU::EmitObjCValueForIvar(CodeGenFunction &CGF,
2394 llvm::Value *BaseValue,
2395 const ObjCIvarDecl *Ivar,
2396 unsigned CVRQualifiers) {
2397 const ObjCInterfaceDecl *ID =
2398 ObjectTy->getAs<ObjCObjectType>()->getInterface();
2399 return EmitValueForIvarAtOffset(CGF, ID, BaseValue, Ivar, CVRQualifiers,
2400 EmitIvarOffset(CGF, ID, Ivar));
2403 static const ObjCInterfaceDecl *FindIvarInterface(ASTContext &Context,
2404 const ObjCInterfaceDecl *OID,
2405 const ObjCIvarDecl *OIVD) {
2406 llvm::SmallVector<ObjCIvarDecl*, 16> Ivars;
2407 Context.ShallowCollectObjCIvars(OID, Ivars);
2408 for (unsigned k = 0, e = Ivars.size(); k != e; ++k) {
2409 if (OIVD == Ivars[k])
2413 // Otherwise check in the super class.
2414 if (const ObjCInterfaceDecl *Super = OID->getSuperClass())
2415 return FindIvarInterface(Context, Super, OIVD);
2420 llvm::Value *CGObjCGNU::EmitIvarOffset(CodeGenFunction &CGF,
2421 const ObjCInterfaceDecl *Interface,
2422 const ObjCIvarDecl *Ivar) {
2423 if (CGM.getLangOptions().ObjCNonFragileABI) {
2424 Interface = FindIvarInterface(CGM.getContext(), Interface, Ivar);
2425 return CGF.Builder.CreateZExtOrBitCast(
2426 CGF.Builder.CreateLoad(CGF.Builder.CreateLoad(
2427 ObjCIvarOffsetVariable(Interface, Ivar), false, "ivar")),
2430 uint64_t Offset = ComputeIvarBaseOffset(CGF.CGM, Interface, Ivar);
2431 return llvm::ConstantInt::get(PtrDiffTy, Offset, "ivar");
2435 clang::CodeGen::CreateGNUObjCRuntime(CodeGenModule &CGM) {
2436 if (CGM.getLangOptions().ObjCNonFragileABI)
2437 return new CGObjCGNUstep(CGM);
2438 return new CGObjCGCC(CGM);